TRIGGERnometry - ＂Will Rats Cause the Next Pandemic？＂ - Steven Belmain

00:00:00.000 How serious is plague in 2022?

00:00:04.040 It's still a big problem in many parts of the world.

00:00:07.080 So just a few years ago in Madagascar,

00:00:10.080 they were taken by great surprise in 2017, 2018,

00:00:14.300 when they had a big outbreak.

00:00:16.420 And it really caused panic there

00:00:18.060 because normally it's a rural disease.

00:00:19.820 It happens out in poor areas of the country

00:00:22.280 and the wealthy and the cities don't worry about it too much.

00:00:26.000 But they got into the city

00:00:27.040 And, you know, there were thousands of cases and several hundred people died.

00:00:37.560 Hello and welcome to Trigonometry.

00:00:40.300 I'm Francis Foster.

00:00:41.700 I'm Constantine Kissin.

00:00:42.880 And this is a show for you if you want honest conversations with fascinating people.

00:00:48.580 Doesn't get any more fascinating and a little bit different to what we normally do today

00:00:52.360 because our brilliant guest today is a professor of ecology at Greenwich University here in London

00:00:57.160 who is an expert in rats. Professor Stephen Bellman, welcome to Trigonometry.

00:01:02.220 Hi, it's great to be here.

00:01:03.360 It's great to have you on the show. Before we get into the very interesting subject of rats,

00:01:09.060 tell everybody a little bit about who are you, how are you, where you are,

00:01:12.220 what has been the journey through life that brings you to be sitting here talking to us?

00:01:15.380 Right, okay. Well, you might hear from my accent as we get going. I'm an American. I'm born in the

00:01:20.960 state of Maine, up in the northeastern part of the states. And so I did my first degree at the

00:01:26.340 University of Vermont. And then while I was there, I did an exchange program and came over to the UK

00:01:30.980 and worked at the University of Kent on an exchange year and fell in love with the country,

00:01:38.780 fell in love with a woman and decided to stay in Britain. So I've been here ever since. I did my

00:01:43.600 PhD on an insect called the Death Watch Beetle. And now I work at the Natural Resources Institute,

00:01:49.300 which is an institute within the University of Greenwich and the institute has a long history

00:01:53.780 of working in overseas development research and linked to the empire and science in developing

00:02:00.900 countries and essentially around the sort of tropical products and how to to live there so

00:02:06.020 issues with locusts and malaria and the problems there so that history of the of the institute has

00:02:11.060 been for several hundred years working in in collaboration with a lot of institutions in

00:02:17.380 in those countries. And so my research is very much based around pest management issues, whether

00:02:22.880 that's rodents, which is a big part of my work, but also other aspects around insects and the

00:02:28.640 management of crops and health issues related to pests as well. And when Francis was suggesting

00:02:35.020 that we get you on, he was like, oh, we've got to get this guy on to talk about the ratpocalypse.

00:02:39.820 Is there a ratpocalypse? So are rats about to take over the world?

00:02:43.720 Well, there's a lot of them. And I mean, people always have these anecdotes. We never

00:02:47.280 farther than six feet away from a rat. I don't really put much in store on that sort of statement

00:02:53.780 because it does depend whether you live in the city or in rural areas. But rural areas have

00:02:57.540 lots of rats too. I mean, if you live on a farm and you'll just see rats everywhere in the crop

00:03:02.960 fields or if it's livestock. So there are hundreds of rats there in cities such as London and New

00:03:07.180 York and Paris. There are big outbreaks of rats. They're living in the sewers. They're living in

00:03:12.200 people's back gardens. And there is worries that the population is growing. I mean, they are related

00:03:16.840 to our own agricultural production, our waste in cities,

00:03:20.600 these are all food resources for rats.

00:03:22.680 So if you're out in the garden feeding the birds

00:03:25.160 or in the park and you're littering,

00:03:26.920 all of that is food for rats.

00:03:28.440 So I think we really need to think more carefully

00:03:31.480 about how we interact in the environment

00:03:34.040 and how we might be exacerbating some of these rat problems.

00:03:37.080 The interesting thing with rats is that wherever human beings went,

00:03:40.440 rats were never far behind.

00:03:42.440 So we've always lived together side by side,

00:03:45.080 even though we found them disgusting.

00:03:47.160 That's right. I mean, if you go down into some very deep coal mines,

00:03:50.520 you'll find rats living down there.

00:03:52.840 And Antarctica, where people have gone for exploration,

00:03:55.480 we have mice living there now.

00:03:57.320 So whether it's a desert or a place where it's just under snow all the time,

00:04:02.760 rats are living there and adapting because we're there.

00:04:05.560 They're taking advantage of our accommodation that we provide

00:04:09.240 and the waste that we produce and the food that we produce.

00:04:11.720 So they've sort of co-evolved with us.

00:04:13.880 And that, of course, has a lot of implications in terms of disease, for example.

00:04:17.760 So because they've been living alongside us, they're going into really dirty environments, down into the sewer,

00:04:23.080 and then coming into our kitchen and spreading those diseases there.

00:04:26.160 So it's a real problem that we've sort of developed ourselves because of the way that we're living.

00:04:32.260 And let's talk about disease, because obviously they were responsible for one pandemic, a very, very serious pandemic.

00:04:40.560 Could they be responsible for another?

00:04:43.040 Yes, in fact, if you think of the plague,

00:04:45.620 which is what a lot of people talk about in terms of pandemics,

00:04:49.160 there are actually three pandemics in the history that were related to plague.

00:04:53.200 So there was one plague before the medieval plague

00:04:55.940 that we talk about as the Black Death.

00:04:57.340 So before that, there was something called the Justinian Plague,

00:04:59.920 which spread around.

00:05:01.160 And then we had the Black Death.

00:05:03.500 And now we are still within what is called the third pandemic of plague,

00:05:07.940 which started in sort of international transport,

00:05:10.880 steam ships going around the world with rats on board and they spread rats to a lot of parts of

00:05:15.800 the world which had before not had plague so to the americas particularly peru and the southwest

00:05:20.660 of the united states also have areas where plague can spread and we're still within that technically

00:05:25.660 a third pandemic still but besides plague there's also been pandemics that have been spread on other

00:05:31.560 diseases so hantaviruses it's a group of viruses but in the time of the aztecs and the spanish

00:05:38.020 colonialists coming over. There was some documented outbreaks of a hantavirus, which

00:05:44.060 called massive population collapses at the time. So we should be worried because of that history,

00:05:49.420 but also, I mean, their role in the current pandemic. We know quite certainly that rodents

00:05:54.980 were not the sort of the development, initial development of the coronavirus. That was most

00:06:00.560 likely bats, but rodents were certainly involved in the Omicron variant. So what happened is,

00:06:06.400 you know, the virus has come out. It is now spreading among lots of different animal species,

00:06:12.800 not just humans. And it's got into the rat population, although to begin with, the rat

00:06:16.820 population was resistant to the coronavirus. But it's got in there and caused a lot of mutations.

00:06:22.680 So that's how Omicron is so different from the original coronavirus variants that were around.

00:06:28.520 So Omicron was essentially probably somewhere in Southern Africa, probably not South Africa

00:06:32.540 exactly, but it was mutating within mice and rodent populations there and then came out as it

00:06:38.360 is now. So we should still be worried about other coronaviruses and the current coronavirus

00:06:43.780 mutating possibly more in rodents. But I mean, there are many other groups of diseases such as

00:06:51.080 arena viruses we should be worried about. One of the most famous arena viruses is Lassa fever, 0.90

00:06:57.320 which is really confined to West Africa,

00:07:00.300 particularly Nigeria, Syria, Lyon, and those countries.

00:07:03.180 But there, we've been observing over the last few years

00:07:06.360 really huge outbreaks in Lassa fever.

00:07:08.440 Again, out of context, we don't understand why.

00:07:11.900 Was this climate change?

00:07:13.300 Is it something that we're doing that's different?

00:07:15.320 But for the last few years,

00:07:16.500 there's been massive outbreaks of Lassa fever

00:07:18.680 spreading in new parts of Nigeria

00:07:21.440 where, in historical terms,

00:07:23.600 they didn't really have much of any Lassa fever.

00:07:25.880 And so there are other variants of Lhasa in the Americas,

00:07:29.060 particularly South America and other parts of Africa.

00:07:31.620 And there are worries about these mutating and spreading to other parts of the world.

00:07:36.080 And we need to be careful and start doing more surveillance

00:07:40.080 on some of these other groups of diseases which could result in a new pandemic.

00:07:45.280 Because particularly when you look at New York or LA,

00:07:48.260 I was reading reports that the bubonic plague has returned to LA.

00:07:52.380 There have been instances...

00:07:53.580 Has there? Oh, right. I haven't heard about that.

00:07:55.160 Is that quite recent?

00:07:56.640 Yeah, yeah, in the last few years.

00:07:57.880 I mean, obviously, there's a lot of problems with homelessness and stuff like that.

00:08:02.020 And it's not surprising.

00:08:03.480 I mean, the southwest part of America where plague is endemic in the wild.

00:08:07.300 So this is like New Mexico, Arizona, quite close to L.A. in that sense.

00:08:11.420 Plague is a disease, like many of these bone-borne diseases, they are diseases of poverty.

00:08:16.620 So they're often found on reservations of Native Americans where conditions are quite poor

00:08:22.080 and people are interacting either with pet cats

00:08:25.920 and the cats acquire plague from chasing rats around

00:08:29.280 and killing the rats and the cats get plagued.

00:08:31.480 And then you're cuddling your cat and it coughs in your face

00:08:34.560 and you get plagued from your cat.

00:08:36.420 But of course, in other situations like LA

00:08:38.480 and sort of poor conditions,

00:08:40.040 it might be through direct contact with rats

00:08:41.860 in some of the situations.

00:08:43.220 Steve, and what is it about rats

00:08:45.380 that makes them so liable to transmit?

00:08:49.180 Is it how closely we live together?

00:08:51.020 Is it how many of them there are?

00:08:53.080 Or is there something about the organism of the rat specifically?

00:08:56.320 Yeah, I mean, it is both of those things.

00:08:58.140 It's the fact that they are mammals, like we are.

00:09:00.960 So, you know, they're quite similar in physiology terms,

00:09:04.360 which is one of the reasons why we use them so much in medical research.

00:09:07.200 And if you're testing new drugs and things,

00:09:08.800 if you first will often test them on model animals,

00:09:11.620 and often that is rats and mice.

00:09:13.580 But it is the fact that they're also very numerous.

00:09:15.880 And a lot of these diseases like plague are density dependent.

00:09:19.320 So when you have a lot of rats at very high density, the disease spreads in their population much more easily.

00:09:26.140 And the fact that they're going from, say, these different environments,

00:09:29.960 they're going to dirty environments where there might be a lot of bacteria and viruses around, 0.90

00:09:34.100 and then they can take those into more clean environments.

00:09:37.000 So that's, I think, quite different from a lot of other diseases we worry about

00:09:41.000 because they're in a single species and they only have like a single disease.

00:09:46.220 But rodents, we know they can transmit more than 60 different diseases to us.

00:09:50.320 Some of those are really scary diseases like loss of fever with high mortality rates.

00:09:54.320 A lot of them are just sort of gastroenteric dysentery type diseases,

00:09:58.300 things like salmonella and E. coli.

00:10:00.080 And they're getting into, you know, our food supply,

00:10:03.260 you know, contaminating in the food processing side of things.

00:10:05.980 Or if you're living out in a rural area,

00:10:07.920 they may be getting in your house and contaminating the food that way.

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00:10:26.400 So what do we do with rats?

00:10:28.640 Because they've always been there.

00:10:30.020 They've always lived with us.

00:10:32.040 How do you control the population?

00:10:33.900 Because we're very advanced.

00:10:35.620 Nobody has been able to do it.

00:10:37.300 Not easily.

00:10:38.200 And I think this is one of the challenges.

00:10:39.840 And I think a lot of people, in the end, they give up.

00:10:43.300 and they just sort of live with a problem.

00:10:45.840 And around the world, we've become over-reliant on a single technology,

00:10:50.340 and that's the use of anticoagulant poisons.

00:10:53.160 So these were discovered by accident, actually.

00:10:55.180 So in sort of the 1940s and 50s,

00:10:58.060 this group of coumarin-type compounds were discovered

00:11:01.260 that they lead to blood thinning and prevent blood clotting.

00:11:04.960 We now use them in medicines and sort of warfarin derivatives

00:11:08.760 to thin our own blood.

00:11:09.880 but in high levels of course it interferes with vitamin k and stops your blood from clotting and

00:11:16.020 the advantage of that with rodents is that they don't notice they are being poisoned so with a

00:11:21.720 lot of the old poisons we used to use they were what we would call acute poisons things that are

00:11:26.520 really really toxic things like strychnine and things that you would use to murder each other

00:11:30.580 which kill really quickly and really painfully but the problem with rodents is i mean they're

00:11:36.060 usually quite cautious when they eat things so they come along and they just eat a little bit

00:11:39.780 and they feel ill and almost immediately so it's a bit like us if we go off to a restaurant and have

00:11:46.480 a meal and that later that day we feel really awful i'm never going to go to that restaurant

00:11:50.580 again you really sort of link the two things together and rodents are able to do that too

00:11:55.300 if they eat something and they feel ill fairly soon afterwards oh that was really bad food i'm

00:11:59.960 not going to eat that and they avoid it so they become behaviorally resistant they didn't eat

00:12:05.140 enough of it to kill themselves so they feel ill but they because they're quite cautious they just

00:12:10.140 take a little bit so the advantage of these anticoagulants that were a fantastic innovation

00:12:15.180 in the 1940s and 50s is that they would eat it and they wouldn't feel ill immediately they'd go

00:12:19.600 home they think about it that was really good food and then they come back the next day and

00:12:23.740 eat more of it and more of it and then they take a lethal dose and end up dying from it several days

00:12:29.860 later often and often they're you know because they feel uh more tired so of course that's what's

00:12:36.520 happening is it's causing internal bleeding and so they feel sort of oh well just go home and go

00:12:41.460 to bed and that's often what they do they go back to their burrows fall asleep and die there

00:12:45.260 and so it gets around a lot of the behavioral issues with rodents part of the problem with

00:12:50.780 these compounds we're having now is that they accumulate in the environment so they don't break

00:12:55.340 down. They've been synthetically designed to last for a long time. And so non-target animals are

00:13:02.280 picking them up. So predatory birds and other animals that might eat the rodents, but even other

00:13:07.620 things that are just in the environment are also acquiring these anticoagulant compounds.

00:13:11.840 So there's a lot of legislation to try to stop using these compounds. And getting that balance

00:13:17.760 right is quite difficult. So some countries are talking about banning them entirely,

00:13:22.180 so we won't use anticoagulants anymore.

00:13:25.140 Others are talking about, well, we need to regulate them better

00:13:27.580 and make sure that only professionals use them,

00:13:30.160 which I think is fair enough.

00:13:31.260 You do need to know how to use these things carefully

00:13:33.640 and to use them appropriately

00:13:35.000 and not just let any old person buy them,

00:13:37.760 which in some countries is the way it is.

00:13:40.520 So we're in this challenge now where if we do ban these things,

00:13:44.420 what are we going to do?

00:13:46.200 There really aren't any alternatives.

00:13:47.780 No one has really done any further research

00:13:50.120 to develop new alternatives for rodent control.

00:13:52.700 There are some new things coming along,

00:13:55.380 but nothing that has been commercialized.

00:13:57.460 So one of the things I've been working on

00:13:59.000 is fertility control, for example.

00:14:00.880 Contraceptives, which we know work with humans,

00:14:04.240 and we actually do fertility control

00:14:05.840 for a lot of other sort of feral animals,

00:14:08.680 whether that's horses or elephants,

00:14:10.300 to control their populations in sustainable ways.

00:14:13.340 But the challenge with rodents, of course,

00:14:15.120 is they're very prolific, they're very short-lived.

00:14:18.300 So how do you get these fertility compounds in them 1.00

00:14:20.700 and deliver that in a way that would still limit their population?

00:14:24.000 So there are very few sort of alternatives,

00:14:26.620 some products on the market,

00:14:28.380 some other kinds of poisons on the market,

00:14:30.400 but nothing really works.

00:14:32.440 So if we ban them, then we have the opposite issue

00:14:36.540 where particularly farmers, livestock farmers in particular,

00:14:39.740 would be, what are we going to do about all these rats on our farm

00:14:41.720 if we can't use poisons?

00:14:43.800 And I would say, I don't know, honestly.

00:14:47.540 I mean, poisons are, you know, mortality control, whether it's poisons or using traps.

00:14:52.760 Traps can work in some situations, but they're very laborious to use.

00:14:56.520 So I think in, you know, Europe and America with these intensive farming situations,

00:15:01.340 having someone go around and set lots of traps all the time is really not very cost effective.

00:15:06.300 However, in a lot of the work that I do in Africa and Asia and other parts of the world,

00:15:10.740 trapping, I think, is a solution.

00:15:12.680 People, you know, can do it in a safe way.

00:15:15.220 They don't need to use poisons.

00:15:16.480 You can reuse the trap over and over again.

00:15:19.420 And that's about communities working together with those traps.

00:15:22.820 And so we've been doing a lot of research on that,

00:15:25.120 trying to look at, you know, in small rural communities

00:15:29.280 where a lot of people are involved in agriculture,

00:15:31.160 living in communities to try to use trapping

00:15:33.480 as a means of controlling rat populations.

00:15:36.240 And it seems to work.

00:15:37.540 The problem is they're so smart.

00:15:39.780 They are smart, but we must remember we are smarter.

00:15:43.460 And I think people forget that.

00:15:46.480 this people think you know they they try to control rats they put out some poison or they

00:15:51.240 put out a trap and inevitably i will hear within the population over time people say oh they're

00:15:58.000 too clever they're avoiding our traps now or they're avoiding the poison which i mean they're

00:16:02.800 they do learn they are behave you know they're mammals like we are they are able to learn

00:16:07.780 there but there are limitations to to what they're able to learn and i think one of the challenges

00:16:13.800 with a lot of animals, again, it comes back to people and our human perceptions. We anthropomorphize

00:16:19.580 things. We give other animals human characteristics. We do this all the time with our pets and our

00:16:25.100 cats and our dogs and think that they're, you know, being able to really love us the way that

00:16:30.440 we love them. But with rats, we do the same thing. I mean, they're too clever to control that, you

00:16:34.900 know, we give them abilities that they really don't have. And one of, again, sort of my jobs

00:16:40.400 when I'm going out working with communities

00:16:42.280 to try to deal with their rodent problems.

00:16:44.780 It's making people understand what are their limitations,

00:16:47.380 what are their real biology and behavior,

00:16:50.220 and how do you use that against them?

00:16:52.320 So, you know, by knowing your enemy,

00:16:54.500 you're able to deal with it much more effectively.

00:16:57.320 And I think people, they want to hear those things,

00:17:00.200 but, you know, they've had so much,

00:17:02.420 they have so much cultural baggage sometimes with rodents.

00:17:05.680 I mean, here in our culture, you know,

00:17:07.040 we've got Mickey Mouse and all these sort of protagonists and stories

00:17:11.660 that are all, they're the good guys, you know,

00:17:13.880 the mouses, you know, the main character in the story.

00:17:16.820 And that, I think, clouds our judgment sometimes

00:17:19.200 and makes them, you know, into these superhuman animals.

00:17:22.940 But so I think...

00:17:24.380 I was going to say, on the other hand, though,

00:17:26.200 a rat's not part, because there are a few types of,

00:17:29.500 a few species that I think human beings evolved

00:17:33.100 a very strong aversion to from very early days.

00:17:36.440 snakes spiders and a rat's part of that because a rat i mean a rat is basically a squirrel with

00:17:42.660 bad pr isn't it like absolutely they're not that dissimilar it's the scaly tail i think

00:17:47.760 you know if you've got a cute cuddly rat it makes a nice pet and you know people will feed it nuts

00:17:53.400 openly in the park like squirrels yeah but yeah the rats and mice i think because they're they're

00:17:58.180 somewhat nocturnal they sort of skid around and that sort of look of the scaly tail is what puts

00:18:03.260 people off i also do think it is related people have been able to sort of put two and two together

00:18:08.220 around disease and hygiene and sanitation issues and so again in our sort of mind we realize these

00:18:15.100 are things from from you know going back thousands of years we really should not be promoting them

00:18:20.100 and avoid them hey kk do you believe in spring cleaning yes but only when my wife does it in

00:18:27.880 the Russian men who clean and executed

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00:19:44.960 And you were talking about population control before.

00:19:48.160 Is that the only way to deal with it, basically to reduce the population of rats?

00:19:52.580 Or is there any way to reduce the way they transmit disease?

00:19:56.140 Well, there are other things we should be doing.

00:19:58.140 And this really, again, comes back to human behavior.

00:20:00.620 It's about sanitation and proofing and hygiene and the way we manage our environment.

00:20:06.660 So in a lot of urban areas, we are the cause.

00:20:12.400 We're leaving food out and the bins are overflowing.

00:20:16.260 The rats just come along and help themselves.

00:20:18.580 If we did a better job at all that,

00:20:20.820 we would have a major impact on rat populations.

00:20:23.940 They just wouldn't, I mean, they need food.

00:20:25.620 If they can't get access to food,

00:20:27.480 then, you know, they're just not going to be so many of them around.

00:20:30.400 So there are a lot of things that are, you know,

00:20:32.320 proposed in rodent professional management.

00:20:35.300 You know, you need to try to make sure the rats can't get at the food sources.

00:20:39.440 That's often very difficult if, say, it's a pig farm or a chicken farm,

00:20:43.040 and there's lots of animal food around.

00:20:45.660 But in urban situations, it really is no excuse.

00:20:48.460 We should be able to do a better job.

00:20:49.780 But the problem is, is we don't prioritize it.

00:20:52.160 We don't really understand the impact.

00:20:54.600 And we're quite removed from it, I think, ourselves.

00:20:56.580 We see them, but they don't really have a big impact on our lives personally.

00:21:00.440 So we can just say, ah, that's someone else's problem.

00:21:03.740 And what do they eat?

00:21:05.260 Anything.

00:21:06.160 I mean, most rodents, we must remember that most rodent species just live out in the wild.

00:21:12.220 They don't do anything of harm to us.

00:21:14.400 They're just eating seeds. They're usually granivorous, so they're eating different grass

00:21:18.180 seeds and other things they find in the wild. They're part of the ecosystem. Thousands of

00:21:22.160 rodent species live that way and don't cause us any problems at all. There's a handful of species

00:21:26.380 we call the commensal rodents, the pest species. So these are things like the Norway rats and the

00:21:31.080 house mice that cause us problems. They are more omnivorous. And I think that's something they,

00:21:36.880 again, because of that omnivorous ability to eat anything they come across, that means they can

00:21:42.320 easily live in a city and live off our waste whatever kind of waste that is and survive on it

00:21:48.020 wow uh you know sorry francis just i i remember when i was a kid i was flying here from russia

00:21:54.780 and there was a guy on the plane with me who was on his way to he ran an english language school

00:22:00.620 somewhere in east asia and he told me the story about motorbiking around thailand or whatever and

00:22:05.220 he told me a story once he stopped at this guy's house and because he was this western honored

00:22:09.700 guest, the guy, you know, wanted to give him some meat. So he, his wife went outside and took a rat

00:22:16.060 off the drying rack and served it. People, how widespread is the practice of eating rats around

00:22:23.000 the world? You'll find it in different cultures around the world. So some parts of Africa and

00:22:27.640 Asia, particularly the rats are seen as a delicacy. So in West Africa, you have cane rats,

00:22:33.520 they're quite a big rat, often not very much of a pest species living out in the wild, but they do

00:22:37.940 get into sugarcane and some sort of crops, because they're so big and meaty, people are actually

00:22:42.660 have domesticated them. So they're actually grown as a farm animal and sold to local markets that

00:22:49.300 way. And other parts of the world, as you say, in Southeast Asia, sometimes they're served at

00:22:53.360 weddings because they're seen as this, again, a sort of an idea of, of fertility. So the young

00:23:00.280 couple should be eating rats in order to go on and breed themselves. And some places they're 0.83

00:23:06.040 sort of tinned up in like little tins that you buy in the supermarket well you can get tinned rat

00:23:11.540 you can mate you look excited yeah in the philippines they have something called star meat

00:23:16.340 rats spelled backwards so if you go to the supermarket shelves there and you find star

00:23:21.880 meat that's rat meat in a tin so it's all been you know hygienically produced and well that's

00:23:26.900 okay then put up yeah yeah so i mean in many parts of the world you know they're they're eaten not

00:23:32.720 just out of necessity but because they really like eating them it has a you know a very distinctive

00:23:36.860 taste and and you know why not as long as they are prepared carefully you're not leading to

00:23:45.500 some extinction you know and in many you know pest management uh ideas you say well if you can't beat

00:23:50.560 it eat it it's one way of we deal with other pests but there is a risk particularly with your if

00:23:55.740 you're catching a rat in the street and and yeah yeah and i think most people that where they do

00:24:00.760 eat rats they make a distinction between say house rats and field rats okay and normally wouldn't eat

00:24:05.900 the rats that are from dirty environments and are trying to to eat them from from the field and why

00:24:11.220 is there a risk of eating a rat as opposed to eating a chicken or whatever well i guess it

00:24:16.240 comes back to just the number of potential diseases they might be harboring and i think

00:24:21.660 often it's down to the to the way rats are cooked so i mean you can get very good recipes and and

00:24:28.800 things that will ensure that they are cooked properly and you don't have to worry about

00:24:32.200 viruses and bacteria being transmitted. But because sometimes they're quite small animals,

00:24:37.020 they don't actually get cooked very well. So essentially they're just held over the open fire

00:24:41.760 and then you open them up and they're still pretty raw inside. And that's where there have

00:24:47.580 been documented cases of people catching plague, for example, pharyngeal plague, where the bacteria

00:24:52.600 gets into the throat and then spreads to the body that way. And many, you know, gastroenteric

00:24:58.340 diseases could be promoted that way, particularly if you're not gutting the animal, you just eat

00:25:02.280 the whole thing, which in some cultures they do. Right. Don't have your rat medium rare.

00:25:07.460 Yeah, make sure it's well cooked. And how serious is plague in 2022?

00:25:15.300 It's still a big problem in many parts of the world. So just a few years ago in Madagascar,

00:25:21.080 Madagascar is a country that's had plague outbreaks almost every year for the last 120 years. So it's

00:25:27.420 a chronic problem there. But they were taken by great surprise in 2017-2018 when they had a big

00:25:35.440 outbreak that got into the capital city in Tenerife and to other urban areas. And it really

00:25:41.160 caused panic there because normally it's a rural disease. It happens out in poor areas of the

00:25:45.900 country and the wealthy in the cities don't worry about it too much. But this particular outbreak,

00:25:51.300 again, it started in the rural area and it got into the city and then it started transmitting

00:25:55.300 human to human which is what you know if you go back to the black death that's how it was primarily 1.00

00:25:59.900 being transmitted first it comes from the rats but then it gets into your lungs and you cough

00:26:03.880 out an aerosol of blood that someone else immediately inhales and catches plague that way

00:26:08.240 so that's what was happening in 2017 2018 in madagascar in the city all the cases were

00:26:14.300 pneumatically transmission transmitted from person to person so it caused panic and you know there

00:26:19.340 There were thousands of cases and several hundred people died.

00:26:23.300 And because I always understood that it was transmitted by fleas.

00:26:27.820 That's right. That's how it still is classically transmitted.

00:26:30.680 So it lives in some rodent species.

00:26:33.000 Again, most of these species, they're living out in the wild.

00:26:35.620 They're not really interacting with humans very much.

00:26:37.760 They act as a reservoir for the plague bacterium in their bodies.

00:26:42.380 And they don't seem to get ill from it.

00:26:44.700 But then what can happen is those rodent species come in contact with other species

00:26:49.020 that are living in our cities, the urban rodents.

00:26:52.480 And so either the rodents themselves or the fleas

00:26:55.460 jump off those rodents and get onto the other rodents.

00:26:58.020 And those rodent species we call are susceptible.

00:27:01.300 So they do fall ill eventually.

00:27:03.000 And so you can get what are called rat falls

00:27:04.820 or mass die-offs of rats in cities that contract plague.

00:27:09.480 And then all the fleas on their bodies leave.

00:27:11.740 And then what do they look to bite?

00:27:13.560 Well, they bite us because we're the only other thing around to bite.

00:27:17.360 and that's how the primary transmission of plague occurs.

00:27:21.260 If it's not treated, eventually it spreads through your body,

00:27:24.920 you get widespread septicemia, it gets into the blood, it gets into the lungs,

00:27:29.200 and that's how you can then transmit it human to human

00:27:31.500 through sort of coughing out blood that's got the bacteria in it.

00:27:35.380 So it's highly transmissible then once it gets to that point?

00:27:37.780 Once it gets to that point, I mean, even at the bubonic form,

00:27:40.920 it's still a very pathogenic bacteria.

00:27:44.080 So with bubonic plague, you get the classic symptom

00:27:47.160 is the swelling of the buboes, the lymph nodes.

00:27:49.900 So it's either in your neck, your groin, or your armpits.

00:27:52.600 You get these big swellings,

00:27:53.920 which in medieval times was well documented

00:27:56.080 and it's a very classic symptom of plague,

00:27:58.060 which no other disease really has.

00:28:00.680 But if you get pneumonic plague,

00:28:02.580 essentially you cough and you inhale it

00:28:04.780 and it just rapidly, your lungs, you have pneumonia,

00:28:09.240 you die from that. 0.76

00:28:10.460 But bubonic plague can also kill quite quickly

00:28:12.300 if left untreated. And that's one of the challenges in many of the countries that

00:28:15.780 continue to have plague. People don't seek treatment quickly enough. Antibiotics will

00:28:19.940 clear it if you go to your doctor and get the antibiotics. But if you live in a very rural area,

00:28:24.980 maybe it's days to get to the doctor and to then recognize it's plague and be treated.

00:28:30.400 It's often too late. And unfortunately, people are dying of a disease that is curable quite

00:28:35.160 easily in the right situation. And what's the likelihood of us having that type of disease

00:28:40.380 in the UK or the US, where we have these huge rat populations, 0.78

00:28:45.200 but we tend to have better infrastructure.

00:28:48.820 Yeah, plague has been used as a terrorist weapon in the past,

00:28:52.760 and there are still worries about plague being used.

00:28:55.500 Yes, it was used by the Japanese on mainland China,

00:28:58.300 so they loaded up ceramic bombs with fleas, infected fleas,

00:29:02.180 and dropped these over cities to try to cause an outbreak.

00:29:07.560 It's more about panic than anything.

00:29:09.640 But, you know, it's a kind of biological weapon, in a sense.

00:29:12.700 The Russians learned how to put it into big intercontinental ballistic missiles 0.96

00:29:18.180 with the bacteria itself.

00:29:20.900 So, the Americans looked into this.

00:29:23.440 We will send your rocket full of reds. 1.00

00:29:25.800 The Americans tried to do this, 0.91

00:29:27.540 but they could never get the bacteria to maintain its virulence in large cultures.

00:29:31.900 But did the Russians succeed?

00:29:32.720 The Russians did this. 1.00

00:29:33.820 And so, they had these huge labs where they were using,

00:29:37.100 you know, growing this bacteria.

00:29:38.620 and they had to keep doing it all the time

00:29:40.120 because the bacteria would eventually lose its virile.

00:29:41.700 So they were recycling the plague

00:29:43.600 in these missiles all the time.

00:29:45.740 So at the fall of the Soviet Union,

00:29:47.940 all these areas like in Kazakhstan and elsewhere

00:29:50.920 where they had these big plague centers,

00:29:54.760 they had to shut all that down. 0.99

00:29:57.500 Fucking hell. 0.99

00:29:58.980 But here now, I think our risk of plague naturally 0.99

00:30:02.220 is very limited.

00:30:03.860 So one of the things we know about plague in modern times

00:30:07.920 is wherever it's endemic,

00:30:09.100 it tends to be sort of a semi-arid environment

00:30:11.100 at high altitude.

00:30:12.740 So if you think of the plateau of Madagascar

00:30:15.500 in the middle of the country,

00:30:16.440 it's quite high altitude.

00:30:17.700 The southwest of America, Mexico, Arizona,

00:30:20.260 again, it's a mountainous region.

00:30:21.820 The central area of Asia where plague evolved,

00:30:24.760 you know, the steppes of Kazakhstan

00:30:25.920 and that sort of area,

00:30:26.960 again, it's a sort of semi-arid savanna-like environment,

00:30:29.760 which is why, again, it spreads a lot in Africa

00:30:31.480 in general in those sort of habitats.

00:30:33.200 So Europe is not a natural place for plague.

00:30:37.340 The climate is wrong here.

00:30:39.380 But of course, in those days, it spread human to human.

00:30:42.640 You don't need the rats and fleas anymore.

00:30:44.260 In fact, we had plague outbreaks in the time of the Black Death

00:30:47.420 in countries like Iceland where there were no rats.

00:30:50.560 So we know at that time there were no rats in Iceland,

00:30:53.180 and yet they had plague outbreaks

00:30:54.180 because it was just going from human to human,

00:30:56.320 either through us coughing out an aerosol

00:30:59.240 or possibly even through human fleas.

00:31:02.260 So in those days, of course, hygiene standards were a lot lower.

00:31:05.180 people, you know, they would move around, they'd have human fleas all through their clothes. People

00:31:09.420 didn't wash very often, their clothes weren't washed. And they were sleeping in communal beds

00:31:13.160 and going to inns, which were infested. Again, stories of, you know, being bitten by human fleas

00:31:18.200 by the thousands. And so we, of course, don't have great evidence of it, but we suspect that

00:31:23.720 those human fleas were probably transmitting plague throughout medieval Europe at that time.

00:31:28.220 And Francis mentioned the huge rat population

00:31:31.780 in different cities around the world.

00:31:35.780 Do you have an estimate of how many rats there are in the UK?

00:31:40.780 More than there are people by far.

00:31:43.340 That makes sense.

00:31:44.280 But it's a real challenge to put your finger on it.

00:31:46.680 It's a lot of effort to try to get those estimates,

00:31:49.300 you know, to go out and do a trapping survey.

00:31:50.800 The ballpark, like there's 70 million people in the UK approximately.

00:31:54.020 Oh, it's at least three times that many rats.

00:31:56.320 So there are 200 million rats living in the UK.

00:31:59.120 I would say easily. It's probably much more than that.

00:32:01.680 There have been some studies that have tried to understand how many rats

00:32:05.520 are killed just in agricultural production.

00:32:08.240 So if you think about the large cereal crops,

00:32:11.760 you've got rats living out in those fields,

00:32:14.480 and they're just living in the soil, burrowing in there,

00:32:17.120 eating the wheat or the maize or whatever it is.

00:32:20.240 And they till the soil, which in itself just chews up lots of rats.

00:32:25.600 And it's literally billions of rats around the world

00:32:29.040 in those sort of situations

00:32:30.200 that are just being destroyed in agricultural production.

00:32:34.140 So here in the UK, of course,

00:32:35.980 there's a lot of livestock farms that are heavily infested.

00:32:38.700 There's a lot of cereal crops where, again,

00:32:41.380 there's just rats living out there, taking advantage of that.

00:32:45.060 And that's in a rural area where, again,

00:32:47.240 we may not really observe it very much.

00:32:48.740 Probably in the cities, I don't think the rat problems are very high

00:32:51.860 simply because, again, it's just access to food and things.

00:32:55.120 So I would say the rural population is probably a lot larger than what you have in urban areas.

00:32:59.480 Yeah, but I suppose the rural population is less problematic, quote-unquote.

00:33:03.580 It's the city rats that we're concerned about.

00:33:05.540 People don't see it.

00:33:05.960 I think, you know, that's the thing.

00:33:07.020 You know, in urban areas, you know, I think, you know, during the pandemic,

00:33:09.720 there was this sort of increase in reporting of rat numbers.

00:33:14.420 And I think a lot of that's because people were sitting at home

00:33:16.120 looking at what's going on in their back garden,

00:33:18.860 and the local restaurants weren't running.

00:33:20.780 And so the sort of traditional sources of food that people had for rats,

00:33:25.760 you know, the bins at the back of the takeaway were not there.

00:33:29.540 So the rats said, well, where else are we going to go?

00:33:31.120 So they went into people's gardens.

00:33:32.480 And so there was a big reportage of more rats around,

00:33:35.540 even though probably the rat population was declining during the pandemic

00:33:38.280 because there was less food around in urban areas.

00:33:40.620 And so what other impact do they have, particularly in cities?

00:33:43.740 We've looked at the disease element of it, which is, of course, huge.

00:33:46.860 But what other impact do they have?

00:33:49.060 Well, I think one of the most traumatic things that I've seen

00:33:51.880 is people who have been bitten by rats.

00:33:54.500 And it does happen here in the UK.

00:33:57.020 I mean, it's not often, but, you know,

00:33:59.180 there are stories in the sort of more tabloid press here

00:34:02.560 of mum being eaten alive by rats.

00:34:05.780 And, you know, this is usually someone who's very ill in a care home

00:34:08.780 and can't fight off the rats.

00:34:10.320 And, you know, they show pictures of her elbow all bitten up

00:34:13.520 by a rat that just keeps biting her.

00:34:15.740 In many other parts of the world, it's much worse

00:34:17.760 where you can see babies with their noses bitten off entirely

00:34:21.300 and, you know, sort of real sort of slum conditions

00:34:23.980 where these rat bites, you know, maybe 10% of the population

00:34:27.460 that's routinely being bitten by rats while you're asleep at night.

00:34:30.700 So you're in your house, you can hear all the rats running around

00:34:33.520 and they're crawling all over you, running over you while you try to sleep.

00:34:37.720 And a lot of people complain of disturbed sleep.

00:34:39.400 But then if, you know, if you're sweating

00:34:41.520 or you've got food residues on your hands or something like that,

00:34:45.860 the rats will come along and just start licking.

00:34:47.760 they're not trying to eat you usually but then you twitch in your sleep and then they bite out

00:34:53.500 in self-defense really so you some pretty grotesque pictures and people that i've seen who've had

00:34:59.860 really terrible terrible experiences where then it leads to infection and gangrene and people

00:35:06.260 having amputations because of it and you know just getting rat bite fever which again is through

00:35:11.600 bacterial infection getting into the wound and spreading through the body so rat bites i would

00:35:16.260 say is one thing that I would try to avoid. In terms of food contamination, it's really hard to

00:35:23.620 put your finger on it again. It's an anecdote. We know rats are involved in salmonella transmission,

00:35:30.860 but to what extent? It's again, it's a question of how much do we want to invest in trying to

00:35:36.420 understand what the real impact is. In food production particularly, I think we massively

00:35:40.400 underestimate the impact, but no one's looking. And I think with a lot of rat issues, we just

00:35:45.900 We don't want to hear about it.

00:35:46.700 We want to brush the issue under the carpet.

00:35:48.760 We don't want to spend money on it.

00:35:50.820 And so we don't know.

00:35:52.860 It's the answer in many of the situations.

00:35:56.460 And what about the aggressive nature of rats?

00:35:58.680 Because that's something that gets talked about a lot.

00:36:00.700 If you corner a rat, it will go for your throat.

00:36:03.600 Is this true or is this just...

00:36:05.200 How is a rat going to go for your throat? 0.99

00:36:07.320 You're 6'1 and a rat is this big.

00:36:10.100 They're not. They're about that big. 0.98

00:36:11.380 Rats can be quite aggressive.

00:36:13.460 But I mean, I think most animals are if they're cornered.

00:36:16.440 So, you know, if you've got one in your garden shed

00:36:18.400 and it can't find the way out to get out,

00:36:21.020 I mean, its response will be to try to attack you to get away. 0.65

00:36:24.160 I mean, some of the Norway rats you get on farms

00:36:28.260 or in urban areas around here, they're very big,

00:36:30.020 sometimes as big as your domestic cat.

00:36:32.780 And if you've got a small cat, I've got a small cat at home,

00:36:35.100 and certainly some of the rats I've seen are bigger than my cat.

00:36:38.040 And if that's battle sort of situation,

00:36:40.340 you can see a rat winning in some of those situations.

00:36:43.460 It's going to go for your throat. 0.99

00:36:45.160 Is that why we're having this conversation?

00:36:46.640 You're scared of a rat?

00:36:48.920 Yeah, I mean, they would certainly try to attack you,

00:36:51.720 but I suspect you would be so scared.

00:36:55.000 Well, you'd be either so scared you'd run out of the way

00:36:57.500 or you would find a way of dispatching it yourself.

00:37:01.580 That's what I would say.

00:37:02.480 And then load it into a rocket and send it to America. 0.88

00:37:04.060 A lot of people would get quite queasy about that

00:37:06.060 and just run away themselves.

00:37:08.440 yeah it's really interesting and and steve what are you working on in terms of your research now

00:37:13.680 are you trying to find solutions to some of these problems or you yeah i mean there's various angles

00:37:19.320 some of it is about sort of developing new alternatives for the poisons and so fertility

00:37:25.120 control is something we've been looking at in a number of different countries evaluating

00:37:29.080 its efficacy so one of the challenges here is that you know you've got a large population of

00:37:34.460 rats that turns over very quickly. So how do you deliver something like a contraceptive to a rodent

00:37:40.300 in a food bait? So it's essentially, you have to put out a bait. It's usually got a poison in it.

00:37:45.020 Will it work when we put the fertility control in there? And again, it comes back to humans and the 0.85

00:37:49.780 perceptions of that. A lot of people say, why are we just going to stop them having babies?

00:37:54.000 We want to get rid of them. And so a lot of it is trying to make people understand that actually

00:37:59.200 this is much more sustainable, more humane for starters, but actually is more ecologically 0.81

00:38:04.740 sustainable than trying to kill them. So if I can try to explain to you what happens when you do

00:38:09.120 mortality control is you kill off a whole bunch of rodents, but you don't kill them all. It's

00:38:13.640 impossible to kill them all. So those that are left recover very quickly. They go through very 0.99

00:38:18.640 rapid breeding and rodents are very good breeding machines. So they can do something called

00:38:24.720 postpartum estrus. So that means as soon as they give birth, they can get pregnant almost 0.98

00:38:29.380 immediately. The next day, they can get pregnant again. So they still have a young litter that 0.95

00:38:33.760 they're nursing. So if it's a mother rat, she's nursing one litter and she's pregnant with the 1.00

00:38:39.140 next. And as soon as those babies are weaned and go off into the environment, she's giving birth

00:38:43.840 the next day. So the gestation period and the weaning period coincide in a number of days.

00:38:50.180 so essentially every month most species of rodent can have another litter of young wow

00:38:55.880 they're just pumping them out so if you kill a bunch what you're doing is you're suddenly opening

00:39:00.880 up the habitat yeah there's a lot of food around because usually the food production is going up

00:39:05.460 this is the beginning of the cropping season and so those babies realize well they have a better

00:39:11.320 survival because there's a lot more food around there's less competition because you've killed a

00:39:14.600 bunch. And so they go through a population explosion, and the population actually can go

00:39:19.900 higher than it would have if you hadn't done any mortality control. So it overshoots. And this is

00:39:26.280 common with a lot of pest issues that we control this way. With fertility control, you stop those 0.98

00:39:31.260 animals from having babies in the first place. They're still there. They're still eating something.

00:39:35.960 But the population, of course, can't exponentially grow as the food production increases.

00:39:40.340 so it's more sustainable but people need to see it at the end of the season in a sense so they

00:39:45.840 have to be patient understand that the damage to their crops is going to actually be lower

00:39:50.160 because you've managed the population and stopped it from going through this boom and bust

00:39:54.020 phenomenon so what we try to do is work with communities so they can understand that

00:39:58.920 but also it's all about timing when you deliver this bait you don't want to just do it all the

00:40:03.980 time so you really want to just deliver it once ideally and have an impact throughout the next

00:40:08.700 few months. So a lot of the research is trying to understand these ecological issues in different

00:40:14.020 sort of contexts to making it work. So that's a big part of my work. Another part of the work

00:40:20.640 is trying to really understand the role between rodent control and disease transmission. So again,

00:40:26.740 it gets quite complicated in ecological terms in the sense you think fewer rats should mean

00:40:30.940 less disease transmission. And with some diseases, that's probably the case, but with other diseases,

00:40:36.280 possibly not. So what can happen when, again, you kill a lot of rats or remove rats, however you do

00:40:42.100 it, those animals that are left might move around more. So they come in contact with more animals

00:40:49.100 further away and possibly spread the disease. So you make matters worse. So trying to understand

00:40:57.140 these dynamics is another sort of fundamental issue. So for example, with plague in Madagascar,

00:41:02.580 we're trying to control rodents. But then what happens to those fleas? And could you actually

00:41:08.320 make matters worse? If you kill those rats, the fleas come off. Are we responsible for causing 0.98

00:41:13.740 a plague outbreak by killing rats? So it's really tricky sometimes. And sometimes these different

00:41:19.260 diseases have different ways of sort of surviving. Some get into water or soil and then are transmitted

00:41:27.160 that way and so that's a another big component of my work is trying to understand what is the

00:41:32.840 best way of managing a rodent population to stop humans catching some of these diseases

00:41:37.920 hey constantin do you love trigonometry i'm from russia i cannot love anything apart from vodka

00:41:46.740 miserable literature and the horrendous downfall of my people but yes i find trigonometry

00:41:52.860 satisfactory and do you like live shows of course but only if it's check-off play about collapse of

00:42:00.300 russian aristocracy as they face death and obscurity before the glorious might of the

00:42:05.660 proletariat and the beautiful revolution okay mate well if you like trigonometry live shows

00:42:12.540 then get your credit card out for the lads because we're coming to the edinburgh festival

00:42:18.780 this august we have only booked two shows august 6th and 7th because if we do more the comedy

00:42:24.460 industry will treat us like the czars and execute us that's right we're going to be in edinburgh for

00:42:30.060 two days only saturday's guest is andrew doyle which is sure to sell out our other guest is leo

00:42:37.820 curse which means when nicola sturgeon hears about it she'll ban us from scotland herself 1.00

00:42:42.620 tickets are sure to sell out and when they're gone they're gone click on the link below and

00:42:48.380 And we'll see you in Edinburgh on the 6th and 7th of August at the gilded balloon Teviot.

00:42:54.800 Come and see us before hordes of left-wing comedians try to put us in gulag.

00:43:00.700 And Steve, there's also a problem as well, isn't there? 0.89

00:43:03.220 The rat is also celebrated or even worshipped in some countries.

00:43:07.380 I remember seeing a documentary about rats and there was a rat temple in India.

00:43:11.500 Yeah, there are those rat temples. 0.92

00:43:13.060 if you look at the Hindu god Ganesh, you'll often see him riding a rat, like a horse. You're seeing 0.85

00:43:19.480 he's perched on top of a rat, and that's his mode of transport. And again, I mean, because rats and

00:43:25.140 their status as a fertility symbol, people reverberate them in that way. And these temples in

00:43:30.640 India, people openly feed the rats because the rats are servants of the gods, again, to Ganesh 0.81

00:43:35.820 and others. So by feeding the rats, you are helping feed your gods in that sense. So it is

00:43:42.820 a challenge in some communities. I mean, if you think of the Buddhist religion, where you shouldn't

00:43:46.920 harm animals, how do you reconcile that with pest control and killing things like rats? It's often

00:43:53.060 quite difficult. And it requires, again, understanding human psychology and why we do

00:43:59.960 what we do in order to really control a pest problem like rats. And what happens when you

00:44:04.720 have like a rat temple, for instance, in India? Does that then become a hub of disease?

00:44:10.640 We have tried, well, not me, but some of my colleagues have looked into that because you get these big basins of porridge and sort of milky substances which are there and the rats are coming along and eating from that.

00:44:24.620 People have tried to test those substances, but so far I think it's inconclusive that we've found that.

00:44:31.000 There is quite high turnover, so you know that food is constantly being replaced because there's so many rats living there.

00:44:36.140 and the people who visit there, I mean, again, you would really have to do quite a careful study

00:44:41.760 and I don't think that's really happened to understand. Again, maybe because people don't

00:44:45.080 want to know the answer. It's better not to know. So it's interesting, our aversion to rats is not

00:44:50.680 universal around the world. No, not at all. I mean, even in European and Western society,

00:44:56.420 people have pets, pet rats, you know, the fancy rats. They're just nicely colored Norway rats

00:45:03.160 or mice. You know, people have them as pets. They're quite affectionate. I mean, most of these

00:45:07.880 rat species that are pests, they're also very social. So, you know, that makes them nice pets

00:45:12.860 because they can be quite affectionate in that sense. So, I mean, there's a huge industry around

00:45:16.600 that, which has also caused some ecological disasters, for example, in the pet trade. So

00:45:22.040 there's a species of rat called the African giant pouched rat. Again, that's a big rat,

00:45:26.940 long-lived species so people like them as pets they have been sent off around the world for pets

00:45:33.860 and unfortunately they've escaped in the to the florida everglades wow and they are now a pest

00:45:39.620 species there that is driving its own uh invasive ecology within invasive pythons so again the

00:45:47.820 pythons have escaped from the pet trade living in the other glades eating these african pouch 1.00

00:45:52.960 rats in the Everglades as well. It's caused ecological disaster in the Everglades because

00:45:57.040 a lot of the native species, they've all been destroyed and out-competed by these species.

00:46:02.800 But also, I mean, these pouch rats have been used very nicely in helping us clear landmines,

00:46:10.420 for example, so that you might've heard of the Hero Rat Program or the Apopo Program.

00:46:14.860 It's developed by some Belgian colleagues and Tanzanian colleagues where they're using the

00:46:20.140 the acute sense of smell of rodents.

00:46:22.000 They're very good at smelling things out

00:46:23.280 and they train the rats to smell TNT in bombs.

00:46:27.180 And so they've learned how to use that smell

00:46:30.620 to then, you know, they would have the rats

00:46:32.680 and they go through this area of field

00:46:34.800 where they suspect there were landmines

00:46:36.480 and they've trained them when they smell TNT,

00:46:39.140 they make like a little digging behavior

00:46:41.020 and then they get a reward,

00:46:43.020 piece of banana or something,

00:46:44.500 and then someone can come in and clear that field of bombs.

00:46:47.820 The way that dogs are used,

00:46:49.200 But rats, of course, are perhaps a cheaper alternative to that.

00:46:53.340 They're also using rats to detect TB and screen tuberculosis,

00:46:57.520 which is a huge problem in many developing countries.

00:47:00.880 And it's really hard to screen normally.

00:47:03.700 It means usually a human staring down a microscope all day

00:47:06.680 and often makes a lot of mistakes because they get tired.

00:47:09.540 But again, the rodents are able to smell the bacteria in a sputum sample.

00:47:14.640 So you can just line up a bunch of these patient samples

00:47:17.080 and the rat just walks up and down

00:47:19.400 and smells which ones have TB.

00:47:22.420 And they're very, very accurate,

00:47:24.500 much more accurate than humans are.

00:47:26.980 That's incredible because there is a flip side to the rat

00:47:29.820 in that we use them, like you said, in medicine.

00:47:33.320 And practically every drug we've ever had

00:47:36.040 has been experimented upon rats.

00:47:37.860 Yeah, and this is, I think, one of the trade-offs

00:47:41.120 or the balances.

00:47:42.400 We want to, I think a lot of people see them with aversion,

00:47:45.380 but I think we have to admire them too.

00:47:47.280 I mean, we use them in many ways,

00:47:49.600 but also just if you think of the diversity of rodents

00:47:52.500 and diversity and biodiversity is really important.

00:47:56.420 And there are really, there are more species of rodents

00:47:58.340 than all other mammals put together.

00:48:00.220 They're, you know, a highly successful group of animals

00:48:02.980 living in the wild.

00:48:04.200 And it's because of these teeth they have.

00:48:06.360 You know, they have these big incisors,

00:48:08.160 allows them to chew through a lot of materials.

00:48:10.540 They have no intention of eating,

00:48:12.120 but allows them to get into new habitats.

00:48:14.160 You know, they can, you know, get through your door or whatever barriers you might try to put in front of them.

00:48:19.800 And so, you know, that evolutionary behavior has allowed them to, you know, be quite successful in the world.

00:48:26.380 So some of them are good.

00:48:28.600 Hashtag not all rats.

00:48:31.280 But I've always found them so fascinating.

00:48:35.380 You know, what is it?

00:48:36.700 What is it?

00:48:37.300 What was the thing that drew you towards them?

00:48:39.900 I really got involved by accident.

00:48:41.540 I didn't start out as a rodent expert.

00:48:43.440 And I think that's something that, you know, some of my colleagues would also come from that background.

00:48:48.400 We often get involved through pest management, which is often focused on insects around the world.

00:48:53.180 A lot more people work on insects than rodents in academia.

00:48:57.200 And so I, you know, when I started working at the Natural Resources Institute, I was a trained entomologist, an insect person.

00:49:04.000 and sitting around the table one day,

00:49:07.520 we had a request from someone in Mozambique

00:49:10.880 asking for help and expertise on rodents.

00:49:14.480 I had done a little bit of work on rodents

00:49:16.760 as an undergraduate at university.

00:49:19.140 So I put my hand up and they said,

00:49:21.160 fantastic, off you go to Mozambique.

00:49:23.420 And I just learned it all there.

00:49:25.220 I was sent out to these villages

00:49:27.180 where people were complaining of mainly post-harvest losses.

00:49:32.120 So this is after they harvested their maize crops.

00:49:34.700 They were storing them in their house,

00:49:36.460 all stacked up inside these maize crops.

00:49:38.820 And the rats were living in the grass thatching of the roofs,

00:49:42.480 just living up there, nesting there,

00:49:44.220 and coming down and eating their maize stored in their houses.

00:49:47.960 And of course, being bitten with plague and all these other problems.

00:49:51.180 And so we started trapping in some of these houses,

00:49:53.480 and I was catching, on average, 100 rats in a house.

00:49:57.360 Wow.

00:49:57.960 These are tiny sort of mud-thatched buildings.

00:50:01.480 One room, everyone sleeps together, and the food is there, the kitchen is there all together,

00:50:06.380 and all these rats are up there, and very little was being done about it.

00:50:10.380 So that kind of opened my eyes to a problem that was being neglected,

00:50:14.460 and I felt, well, we need to do something about this.

00:50:17.780 Poisons weren't really an option because they were eating rats in these communities 0.90

00:50:21.140 as well as a source of protein, and so we started this trial on how can we just trap them out?

00:50:27.120 Can we trap them intensively enough with the labor on hand in all these households 0.67

00:50:31.000 to do something about it.

00:50:32.860 And from there, you know,

00:50:34.020 I started making contacts with the rodent community.

00:50:37.200 I'm not the only rodent expert in the world.

00:50:39.260 There are many very well-respected colleagues

00:50:41.400 who've been doing it longer than I have.

00:50:44.240 And so I started talking to them

00:50:46.020 and then developing more grant proposals

00:50:48.640 and doing more research in different parts of the world.

00:50:51.560 But we've also touched on the impact they have,

00:50:54.720 the negative impact on ecology.

00:50:56.780 Like you said, the Everglades

00:50:58.000 and wherever human beings went,

00:50:59.420 rats were very close behind and then they succeeded in wiping out they do they're invasive

00:51:05.020 and you know this has been a big problem on islands around the world where again you've

00:51:09.760 had these sort of bird populations that aren't used to having rats around we've accidentally

00:51:14.560 introduced rats and they just devastate the population you know they're they may be flightless

00:51:19.480 or they're putting their nest scenario where the rats can come along and attack the the chicks and

00:51:23.360 eggs in their nests and so yes we have tried to reverse that so there are some people who have

00:51:29.240 learned how to very efficiently remove rats from islands at great expense, but you can be done.

00:51:35.620 And we've done this quite successfully in many small islands and even some large islands.

00:51:40.140 New Zealand is even trying to do this across the entire New Zealand, you know, two big islands.

00:51:45.580 They have a program to remove not just rats, but all introduced species. So which again,

00:51:51.780 have caused ecological disaster in New Zealand for a lot of native bird species and things. So

00:51:56.880 So they are essentially starting on this idea where we will clear parts of the island and

00:52:02.720 then they put a huge wall around that part to keep out all these invasive species.

00:52:07.260 And then the idea is those walls will expand and expand as they clear more and more of

00:52:11.360 New Zealand of all these invasive species.

00:52:13.640 So I wish them luck, it's a huge challenge, but they seem very dedicated to it.

00:52:19.140 It's often a family activity to go out hunting on the weekend, trapping these species out,

00:52:25.300 just rats but you know opossums and other things that they've had there to try to bring New Zealand

00:52:30.240 back to the way it was before all these invasive species came in. And how likely is it that they're

00:52:36.120 going to achieve their goal? If they're if I think they could if they're you know they have to put

00:52:42.680 the money into it and the manpower into it and you know if they keep it up and they seem to this

00:52:47.560 there's a lot of buy-in by the community you know the people of New Zealand have you know they

00:52:52.420 They understand this is important and this is what will do it.

00:52:56.420 If the population is behind it and puts the money into it and the labor,

00:53:01.720 I think they could do it.

00:53:02.760 It may take a while, but they already do have some big parts

00:53:06.160 that are sort of already cleared around some national parks

00:53:09.960 and things like that where they've been able to do this successfully.

00:53:12.540 So it's just a matter of being able to expand that

00:53:15.040 across greater and greater areas of the country.

00:53:19.260 And where do they originate from then?

00:53:20.920 So it's not from Australia or New Zealand or those from South America?

00:53:25.720 Well, it will depend on the species.

00:53:27.120 If we're talking about ratus, so we have ratus ratus, which is the black rat,

00:53:31.660 which we don't really have here anymore, but it used to be a big problem here.

00:53:35.160 And now we have Norway rats, ratus norvegicus.

00:53:38.180 So ratus is a genus that evolved in Asia, particularly Central Asia.

00:53:43.940 So that's where the ratus species are.

00:53:45.320 So if you go to Southeast Asia, you will find a large diversity of ratus species.

00:53:49.740 and they're all quite similar.

00:53:51.280 They all often look the same.

00:53:52.400 It's really hard to tell them apart,

00:53:53.760 but there's a big diversity there.

00:53:56.180 In other parts of the world,

00:53:57.440 they have other groups of pest species.

00:54:00.080 So for example, in Africa,

00:54:01.560 the main genus is called Mastomus

00:54:03.760 or the multi-mammoth rat. 0.98

00:54:05.720 It has lots of nipples 0.98

00:54:06.780 and able to have very large litters. 0.99

00:54:08.940 So it's a big problem in Africa.

00:54:11.200 So there are these sort of global invasive species

00:54:13.680 like particularly ratus and housemus, mus musculus.

00:54:17.280 These are the species that have really spread around

00:54:19.700 in urban environments and when they have invaded new places they've often you know resulted in

00:54:25.220 extinctions and other things being removed from that those areas but then there are often sort of

00:54:31.140 local pest species so in south asia you have bandakota species which again look quite distinctive

00:54:37.220 you get them in india and bangladesh and pakistan and they really are confined to to that region

00:54:43.380 steve it's been an absolute pleasure and fascinating conversation before we ask you

00:54:48.020 our questions from our supporters. We always end the show with one final question, which is,

00:54:53.040 I know you're probably going to say Raz, but I'm going to ask it anyway. What do you think is the

00:54:56.420 one thing we're not talking about as a society that we really should be? Well, I mean, the

00:55:00.780 institute I work at is very much involved in overseas development research. So I think that's

00:55:05.980 one thing I would like to highlight is that I think we sometimes live in a bubble and we don't

00:55:10.720 realize how difficult it is in other parts of the world. And I would really encourage people to start

00:55:16.140 thinking about how can we support more research to deal with some of the problems that we have

00:55:21.900 in say Africa and Asia. Some of these issues are really simple to deal with, but we just need to

00:55:27.400 do some basic research on it. So I would really hope that people will think more about what other

00:55:33.720 people have to go through living with rats or whether it's other pest problems. We hear about

00:55:38.740 malaria, but there are so many other neglected problems and you really have to make an effort

00:55:43.580 to inform yourself about some of these issues sometimes

00:55:45.960 because there's just so many competing interests.

00:55:48.620 And rats, I think, are neglected

00:55:50.020 despite myself spending so much time on it.

00:55:53.180 There are very few of us working on this.

00:55:55.160 And there are so many other neglected issues like this.

00:55:57.400 So try to go out and inform yourself

00:55:59.280 on some of these developing issues.

00:56:00.680 And I would say one place to look at

00:56:02.520 is my own institute, Natural Resources Institute,

00:56:04.960 to try to find out some of the other things

00:56:06.300 that we're doing.

00:56:07.900 Steve, it's been an absolute pleasure.

00:56:09.740 If people want to find you online,

00:56:11.300 where is the best place to do that?

00:56:12.600 Go to the University of Greenwich Natural Resources Institute

00:56:15.200 and there's a little page up there about all the staff involved.

00:56:19.880 So just Google my name and you will find plenty of links that way.

00:56:23.760 Professor Steele Bergman, thank you so much for coming on

00:56:25.720 and thank you guys for watching and listening.

00:56:28.160 We will see you very soon with another brilliant interview like this one

00:56:31.240 or our show.

00:56:32.660 All of them go out at 7pm UK time.

00:56:34.580 And for those of you who like your trigonometry on the go,

00:56:37.460 it's also available as a podcast.

00:56:39.300 Take care and see you soon, guys.

00:56:42.600 Do they really come up the toilet or is my local plumber having me on?

TRIGGERnometry - July 11, 2022

＂Will Rats Cause the Next Pandemic？＂ - Steven Belmain

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