The Infinite Monkey Cage - Bats v Flies

Episode Date: July 23, 2022

Brian Cox and Robin Ince kick off the new series by tackling one of the greatest questions ever posed by science: which are better, bats or flies?Joining them for this unusual version of animal Top Trumps are a bat expert (Prof Kate Jones), a fly expert (Dr Erica McAlister) and Dave Gorman. Pitching arguably two of the least-lovable groups of creatures against each other, the battle for victory explores why we should favour flies or find bats beautiful. Although both are much maligned thanks to their association with some nasty diseases, Erica and Kate battle furiously to show why their respective species should be loved not loathed and how our planet would simply not be the same without them. Dave Gorman joins the panel in an attempt to help adjudicate.Executive Producer: Alexandra Feachem

In our new podcast, Nature Answers, rural stories from a changing planet, we are traveling with you to Uganda and Ghana to meet the people on the front lines of climate change. We will share stories of how they are thriving using lessons learned from nature. And good news, it is working. Learn more by listening to Nature Answers wherever you get your podcast. As women, our life stages come with unique risk factors, like high blood pressure developed during pregnancy, which can put us two times more at risk of heart disease or stroke. Know your risks. Visit heartandstroke.ca.

or stroke. Know your risks. Visit heartandstroke.ca. BBC Sounds. Music, radio, podcasts. Before you get stuck into this episode of the Infinite Monkey Cage podcast, here's a little reminder that if you're in the UK, the new series is available first on BBC Sounds. It's a doddle to download the BBC Sounds app and subscribe to the Infinite Monkey Cage. Once you have, you'll get all those irreverent insights from the brightest scientific minds 28 days before they're available anywhere else, which ironically is a bit of a no-brainer. Now, over to Robin and Brian. Welcome back to the Infinite Monkey Cage. I'm Robin Ince. And I'm Brian Cox. We've been away for some time, or we've been away for no time. Depending on your understanding of time.

Yeah, this is really, I suppose, because some physicists suggest that we may seem to experience the passing of time, but that's just our delusion, which is why more of them are being employed by parcel delivery companies. Then again, physicists also tell us that we're holograms, that, in fact, we are merely projections, two-dimensional images, which is insane. It's not. It's a consequence of the thermodynamics of black holes.

Bekenstein showed that black holes have an entropy, which is proportional to this. Okay, right. Anyway, so for the purposes of today, let's just presume that the passing of time has occurred, so we're sorry we haven't been about, but now we are here as well, and we've always been there in the block universe too, so don't worry about that. What's today's show about robin today's show is about flies flies and bats what the entropy of bats i always know that when it comes to us dealing with any form of biology in some way you will turn it to being something about physics if you throw a bat into a black hole like two bats

throw two bats into a black hole by the way this is something you will never get past an ethics committee if the first line is i would like funding for throwing two bats into a black hole that will not get passed anyway look we're gonna do biology i don't care whether you want to deal with entropy right and so today we are going to explore probably i would say the most profound question in biology which which is bats or flies, which is better? To debate this profound question of central importance, we're joined by a bat expert, a fly expert, and a referee who will ensure fair play between the two,

and they are. Hi, my name is Dr Eric McAllister, and I'm a senior curator of flies and fleas at the Natural History Museum. My favourite bat, actually it's just one bat, her name was Susie and she's a Jamaican fruit bat, and I hand-reared her when I was in the Caribbean and I hadn't realised that bats purred. And she used to sit on me and purr. And I've just lost it for flies saying that, I'm really sorry.

I've just lost it for flies saying that. I'm really sorry. Hello, I'm Kate Jones. I'm a professor of ecology and biodiversity at University College London. And I guess if I had to say my favourite fly, I would probably go for the most dangerous animal on the planet, which is a mosquito. It's not. It's not. You know it's not.

We'll deal with this later on. Hello, my name is Dave Gorman. I'm a university dropout. My favourite fly is butter. And my favourite bat is wom. And this is our panel. I just want to clear up. So I thought mosquitoes were the most dangerous animal. They transmit, they're vectors,

but a mosquito itself, she doesn't kill you. So you can't blame her. She's just being a mother, doing what she's put on the planet to do and you're having a go at her she's being manipulated full stop by the you know everything going on those plasmodium no one has a go at them it's not just plasmodium is it though it's all the other things that take advantage of her she's obviously it's like dengue fever chicken gunya i know there's a brilliant name for a virus. But, you know...

A few things. A few things. But mosquitoes do a lot of good as well. malaria, Zika. And it's not her fault. No-one cares about this. I worry about this with fleas as well, because more fleas die during the plague than humans.

Again, I say no-one cares about that. And these sort of things, you know. This is a fascinating thing to see entomology playing the victim card. Yeah. Which I've just... Well, I worked out, if you... Like, the only way a mosquito could kill you personally is to exsanguinate you, so drain you of blood.

Now, it would take about 414,000 mosquitoes in one feeding event to drain you of blood enough for you to die. And we physically don't have that much skin. Do you? Okay, let's... I don't really understand how I'm supposed to referee this, but I'm pretty confident it's right now it's 1-0 to the bats. It was the more

flies died in the black plague. That was it for me. Fleas. Fleas, yeah. I was interested. I can't care for fleas. I'm sure last time you were on, you were curator of flies at the National... No, I'm flies and fleas.

It's a promotion. What? I love the idea that you go, well, it started off as an infestation, but then we thought we could turn it into a promotion instead. Fleas, they're very closely related to flies. Okay, they've got the issue of no wings, but a lot of flies have no wings, so that's fine.

Well, I'll tell you what, let's start the show, actually, because I can see now our producer's gone, well, none of this is what we were meant to be talking about. But no, I love it, it's my fault. Let's start with you, Kate, on actually the first kind of, well, the only round, I suppose. We're going to give you one minute, so we've stolen a bell from Sue Perkins

that she likes to use for just a minute. There's a lot of pressure Yeah Can I just interject here because it's not really an unfair question is it because you're a professor at UCL and you're here because you're an expert on bats and all he said is can you give us a minute on bats? Fine

I can do that, fine I'm just trying to get the parameters of the competition. That was all. Professor, please give us a minute. In a wreathian manner, educate, inform and entertain on the subject of bats. Right, bats are awesome. They're over 1,400 species. They're the largest group of mammals on the planet, apart from rodents.

And they're found all over the world, apart from the poles. There's a huge range in sizes, from the bumblebee bat, which is the size of a bumblebee, two grams, to the false vampire bat, or the Indian flying fox, which is one and a half kilograms. They're important pollinators and seed dispersers, over 500 species are pollinated by bats and rely on bats. That includes mangoes, durians, avocados, and of course agave plants, which make tequila for margaritas. They're an important controller of insect populations. In the US alone, the service is provided by bats, so you have over 23 billion a year in pesticides not being applied. They're the only mammal capable of a powered flight. They include the fastest flying mammal in the world,

flying animal in the world, 160 kilometres an hour, the longest-lived animal for their size, 41 years. No, it's all right, because it's not that game. You're allowed to go on a little bit longer. There were, like, two more things I needed to say. Yeah, that's fine. They're good at repairing DNA. They've got sophisticated use of echolocation

and their squeaks are louder than a rock concert. 140 decibels, which is 15 decibels higher than our pain threshold. I just want to object to one thing, though, because they're not the only mammals capable of powered flight, are they? No, they are. Because Neil Armstrong... Oh. Oh!

By the way, if you've ever wondered, he's really annoying at pub quizzes. OK, they're the only non-human animal... Capable of powered flight. You say they repair DNA? Yeah. I mean, genuinely, is there some practical purpose that we can take from their repairing of DNA?

Yeah, there is, actually. So bats are these amazing flyers some practical purpose that we can take from their repairing of DNA? Yeah, there is actually. So bats are these amazing flyers, and it means that you have to have a really high metabolism in order to power that fly because it's really costly. And that puts enormous metabolic pressure on cells, and it means that they get oxidative damage quite a lot. And so oxidative damage damages DNA, and they've evolved to kind of cope with that and repair DNA.

So they're really, really good at repairing DNA, and those are things which cause cancer, for example. So bats hardly ever get cancer. And also they're just really good at fighting infections. So we could actually learn from them about how they deal with horrible diseases. And yet, bats and horrible diseases and yet bats and horrible diseases there's a sort of elephant in the room here right now isn't there we're casting a shadow over the

last few years of our lives if you get bitten by a bat you don't suddenly get a cure for cancer you get a bloody pandemic okay well can i just i'll just address that straight on i think really it needs to be addressed so um the reason for this covid pandemic is about our actions rather than any particular animal like demonizing a particular wildlife species is never going to be helpful because it's how we've transformed the landscapes which have made us come into contact with different animals and in different situations than ever before. So all species have their own microbes and own pathogens. Every single one of us in this room and every species on the planet.

But it's just how we've changed that transmission dynamics means that we're creating these really unhealthy landscapes for us and for wildlife and it means that those microbes can have a bigger chance of getting into the human population um erica let's move on to you now uh so as you know it's slightly changed now it's what is better bats or neil armstrong and you have one minute on Neil Armstrong. Starting now. Well, actually, the first animal in space was a fly. So I just say that in 1947.

And that's the nice way to start. Now, there's a lot of them. And I know a lot of people won't like the fact there's a lot of them, but we do need them. There's 165,000 described species so far on the planet. There's over 7,000 alone in the UK. So they absolutely dominate. And we need them to dominate because they're so important when it comes to all ecosystem services. So you would often come across a fly when they're maybe, I don't know, rolling around feces.

And you might not like that. But just imagine if they weren't rolling around in feces. You'll be swimming in a quagmire of it with a long dead relative floating along beside you. So they're really important recyclers of the planet. They're really important pollinators. Yes, you have tequila, but I'll give you chocolate. And more people like chocolate, and that's because of the flies. They're really important as predators,

and they're not just really good predators. Some of them are completely amazing, because a lot of them are venomous. Oh, my God, I haven't even started! That's what happened to me. You were even better this time in putting people off their tea. In fact, not only did you mention dead bodies in excrement, but then you went straight into chocolate.

So you made the link so clear. I don't like chocolate. Right, I'm just going to say silk production, bioluminescence, smart needles and cryo freezing. They can go, they can desiccate and they can go into liquid nitrogen. Back off.

So just the liquid nitrogen thing then. Just run us through that. Right. It's called a sleeping coronamid. And actually, NASA are looking at the sleeping coronamid because it does all sorts of crazy stuff. And I'm a bit nervous because Brian's sitting there and I'm like, oh, I'm venturing too far out of my territory here. But this coronamid, it's called a sleeping coronamid.

It lives in the desert. And when it lives there, obviously, these are non-biting midges, sorry. And the larvae live in little water bodies. and water bodies desiccate quite quickly so they make a little cocoon out of mud and they stand up in it this little maggot and then they basically just desiccate and they desiccate 90 of their body that's it three% is liquid left. And therefore, they are able to survive extremes. And in a lab, they lived for 17 years like this. Now, what lovely scientists are doing, are being really horrible,

they're trying them out in all sorts of different things. So they've boiled these. It gets worse. So they've boiled them at 100 degrees for five minutes, and then they've taken them out and put them in normal water like room temperature and they gradually rehydrate and they're fine and they carry on to adulthood so they thought okay let's try something more so they've boiled them at five minutes at 200 degrees and they've survived they have taken them down to minus 190 degrees for a couple of minutes.

And again, they've survived. They've taken them to minus 260 degrees and they've survived. They've put in 100% ethanol and they've survived for seven days. They have thrown radiation at them. And they can, is it greys? Yeah, they can survive 7,000 greys. greys so i mean they're a bit weird afterwards that definitely is but these little creatures can do all sorts of amazing what do you mean they're a bit weird afterwards you've got to run me through that well are all these experiments hosted by

anton deck well they don't these ones haven't made it to adulthood so they will survive a couple of weeks but the fact that they have been revived because they go through what's called cryptobiosis they they it's not like a hibernation they they just they don't metabolize one bit it's interesting so so essentially you said they can survive for well almost ever in this. One reason is because all the water comes out. And I suppose that's why you can freeze them. Because the thing that destroys organisms when they freeze is the expansion of the water in the cells, isn't it? Yeah.

So I understand that. But in terms of boiling or subjecting to very high temperatures, you would think that the proteins and the structure of the thing would break down. But I suppose the question is why because obviously you know from an evolutionary perspective um is it just a byproduct of the fact that these things can be frozen at normal temperatures but it happens that you can take the thing down to minus 170 i'm guessing that i'm guessing they didn't think... Where do they live, Erica? Do they get desiccated quite often? Not to that extreme.

Yeah, they will get desiccated a lot, but they are not going to be subjected to boiling temperatures like that. I mean, the water bodies will... They will get very hot, but they're not boiling lakes. When they're not having these awful experiments of withstanding torture, in their natural habitat... what do they actually do

everything because the reason i want to survive is because i want to watch homes under the hammer tomorrow i want to read a book i want to go for a bike ride i want to hang out with my wife and my child that's why i like surviving but these things i sort of get the impression they're really good at surviving but then they don't take advantage of that okay the idea that the fly's failure to enjoy homes under the hammer may well be its reason to be destroyed from the planet i just want to know what they do they have a lot of sex they They have a huge, their fertility rate is one of the reasons they're the model organism on the planet. Animals. So Drosophila, why Drosophila became such an amazing lab animal was because basically the turnover, they were small,

they ate basically bananas, it was great, and they were very reproductive. So they were able to do very complicated experiments. When previously, when they were looking at genetics, they were able to do very complicated experiments when previously then they're looking at genetics they were using hairs and that's just a long time of waiting what range of lifespans do flies have what's the shortest lived and the longest lived well shortest lived for the whole lifespan this is what we're going to talk about the whole lifespan is a couple of weeks but there are some adults that only survive for two hours the the male actually the male survives for two and a half hours and the female is half an hour

as an adult it's rapid that has made the and they go through this experiment and survive into adulthood seem less impressive. It's like... But bats, on the other hand, live an inordinately long time, don't they? Yeah, they're the longest-lived mammal. If you do a whole graph of lifespan along the bottom and size, they're outliers because they live... The kind of similar-sized mammal to a bat, say, would be like a little mouse,

which would be living 18 months or something. And the similar-sized bat would be 41 years or something like that. So it's because of this kind of DNA repair mechanism that they have, we think. So 40 years? That's their record, 41. I just wonder if they could have lived even longer, and then one scientist went, it's lived to 41. I wonder if it survives in liquid nitrogen.

Oh, no, it doesn't. There we go. I find it interesting, though, you know, looking from an evolutionary perspective, it's interesting that you could ask the question, why only live half an hour as an adult? Or you could ask the question, what advantage does a bat have for living 40 years? I suppose you're suggesting it's a side effect

of its ability to repair itself. And it's also a side effect of the fact that it has very little mortality so that it tries to optimize you know it's a life is a huge optimization game right so that you grow as large as you can be and then you start reproducing and you know evolutionary in evolutionary terms and so bats have very low mortality. They take ages to kind of get to adult size compared to a similarly sized mammal like a rat or a mouse. So they just like live in the slow lane. They give birth to one baby each.

You know, they have a low reproductive turnover, which makes them more vulnerable to, you know, things that might happen, like, you know, deforestation or a disturbance, disturbing a roost, because they have such a slow life, slow reproductive strategy, they, they kind of totally kind of really focus on living slowly. And so if anything disrupts that, it's a big problem for them. slowly and so if anything disrupts that it's it's a big problem for them that's interesting because there's a lot of flies that only give birth to one young at a time and these flies are found on bats are they yeah yeah no that's that's why i met suzy because we were checking out for flies on bats who's suzy my little fruit back from i always see. And honestly you don't pay any attention. I know, I do.

It was such a pity because suddenly there was common ground. I know, we had it. And she blew it. It's the perfect second reel of the movie. Hey, they're getting on. Oh no, in this Mills and Boone romance, they've fallen apart again. These are wingless flies living on bats. And they give birth to one?

They give birth to live young, so the flies themselves get pregnant. Yeah, they've got internal lactating glands what tits on the inside and they they will nurture i don't know if i'm allowed to say that for radio four yeah also if that is not going to be sampled within the next year by someone i a tits on the inside is inside it might not be a Christmas number one but I could see it being an Easter number five the lifecycle of the bat flight was it cold by the way there's there's two fat well we're arguing because we may sink them into one family but there's Nick Terry beards and the streps shabby day and they most of them if they've got wings they won't have them for long some arguably the weirdest bat weirdest fly i think i know of one is that and when she gets pregnant she then uh

sticks her head in the side of the bat and she rips off her wings and her legs and then she basically invaginates her abdomen over her body so she looks like an inverted pear so it just looks really weird but yeah and she will then give birth to maybe four five young i love the fact again someone at home they've given up on their chocolate they went i'll just have this pear oh this is getting ridiculous how does she always know these flies the their offspring is like 40 of of their body weight. That's true for bats too, actually. We have common ground. We've got to do right and paper on this.

There's a word, invaginate. That's not just tits on the inside, that's everything on the inside. Imagine pulling your butt cheeks so far apart and then wrapping them over your head. It's a really interesting period of a show, isn't it't it where you go does this one just become the legendary one that never went out this is and it seems to me but i i'm fascinated well actually just in terms of these things like the loss of wings the idea that there is something that you develop that you will use very very briefly it will then be destroyed because its function has been reached yeah loads of flies do it.

There's a group of a family of flies called forids, the horrid forids, because they're quite difficult to identify. But there's the ones that live in coffins, so they're very important for forensics. So if you were to bury a body, please, I don't want to know about it if you do, when they talk about them being six foot under,

because these flies, the males will lift the females up. Sometimes they don't have wings to start with at all. But if they do, they kind of throw them down and the female then rips her wings off to enable her to bury down to the coffin, to the corpse, to lay her eggs on it. Which is, I mean, how that starts in the first place,

the evolutionary advantage of, like, those sorts of things happen, and I just think are quite fascinating. There are some bats which haven't lost the ability to fly but they do like hopping and running on the ground see that's what i wanted to ask you about so that i'm fascinated with things like the development of of well at what point we see the ancestor of the bat that there is the mammal that flies because there are so few mammals that do fly yeah it's a bit of a contested issue actually we think it's probably an animal that was arboreal in a tree was kind of leaping off those trees to start to fly you know and spreading

wings and then that evolved into into flight but the flight in bats is really different to birds but bats are called chiroptera so which means hand wing and it means that they have expanded their their hand basically into a wing but some of the wings have evolved into they use them to jump so the vampire bat there's only three vampire bat three bats which drink blood out of 1,400, just saying. I mean, I went to a school with 1,400 kids in it, and someone said, only three of them drink blood. We'd think that was pretty bad odds. See what he's saying there.

But they do... So vampire bats can leap really high into the air from a standing start because they need to get on to the things that they're drinking, like cattle, for example. But this is great. But, like, hoverflies can do all of this, but better. You know, they do jump jet. In fact, there's lots of people at Imperial right now looking at hoverflies for jump jet technology

because they're amazing at their vertical lifts. They can, like, stay midair. They can yaw, they can roll, they can fly upside down. They can do all of these. Huge migrations as well. There's a fly that flies over from Africa to the UK. So this little thing, not a big flappy thing, little thing. People forget how amazing these wild animals

flying around your living room really are. Well, that's... I mean, you know, at the beginning, we were talking a little bit about the fact that both you are dealing with uh you know creatures that are vilified and and have been vilified in popular culture and generally as well do you feel you're beginning to win the war to stop people swatting them away no um i i hope so and i've just i've just the fact that it's really hard to swap them have people not thought about this so the processes they are they are they've got such fast neurological pathways so they see everything there's just their eye facets you know they may only have 5 000 eye facets which is like the

omitidia so dragonflies have 36 000 what bats have two eyes two just saying but um you know you've got all this and they but it, how they differ from the other insects is that their photocell, which in the other insects is eight fused together, the flies have got them all separated again. So they are seeing all these multiple angles. Then why can't it find the open window? No, there's a difference. There is a difference.

That's a brilliant question. No, no no i have been asked this a lot i have been now they they see in uva uvb okay so that is refracted by the glass anyway so they've got weird things going on plus loads of things land on the window they taste with their feet so they're tasting all sorts of strange things going oh you know what your house is filthy i don't know you personally but your house is filthy and they can smell it from age you know far far away so they're in there why would they go outside when they've got a warm like very nice protective environment they don't register home ownership they don't get it that's one of my issues with them. It's one of the reasons you're always watching Homes Under the Hammer. You can't live in this smelly old house full of flies.

I've got to find somewhere else to live. I mean, you mentioned echolocation, and that is, you know, Erica, you know, went, oh, they've only got two eyes. But I remember someone once saying, how do bats get around? They basically just shout at things to find out where they are, which is such a beautiful description. Oh, there's something over there. So can you run us through a little bit about how that works then and what we know of how it works? Yeah, I mean, it is really fascinating

that they've evolved this capacity to emit sounds and then bounce those sounds off objects and then understand how the frequencies are changing as they come back and interpret that and then turn that into an actual shape or where they are or what the object is. And in fact, that kind of abilities can be trained into humans and some people that are visually impaired

have been using that kind of technology and actually training themselves with clickers and to click and interpreting the echoes when they get back. And there's some really fascinating studies where, you know, somebody who was visually impaired actually saw the stairs from their house for the first time after training their brain into having this input of sound rather than vision, which is really fascinating, you know, when you think about how that actually works in your brain.

You can actually, because it's actually, the brain is actually in a case in a dark darkened case right so it's just getting input of light from your eyes but that's the same kind of input you're getting from these echoes as they're bouncing into your into your ears instead so i think it's a really fascinating area and there's like huge arms races going on between insects and bats so moths some moths can hear sneaky moths yeah so some of them can hear bats actually echolocating and will take evasive action so they'll fold up their wings and drop out the sky for a bit just to get out of the range or bats can do countermeasure where they can go silent for a bit just to eavesdrop on the moths or some moths will jam bats so they make a jamming signal and so the bat's like whoa what's happening

and can't spot them and it's not just insects either like plants do it so some plants have evolved leaf shapes which are parabolic and so when the bat is coming in to pollinate it kind of says i'm here i'm here you know in to pollinate, it kind of says, I'm here, I'm here, because it's got this lovely kind of shaped leaf, which sends the signal back out to the bat. It's like waving flags at the airport, like park here, park here, come in. I did just want to explore very briefly,

you mentioned pollination there. We've talked about the threats from insects mosquitoes bats and so on what would you say to people who think particularly let's talk about mosquitoes for example it seems as if it would be a good idea to remove mosquito just very naively given that malaria is is probably the greatest killer of humans. So why is it that we shouldn't consider controlling species that are dangerous to us? We can both answer this. OK, so there's 3,500 described species of mosquito,

and they occur all over the planet, in cold regions, Arctic, and warm regions that we know. And of those 3,500, 150 of those species are important vectors for these diseases. Maybe about 20 of them are the ones that really do all the damage. But that's only the females that are the vectors. The females and the males are also pollinators, massively. The males will never blood feed, so they go around pollinating. Now, we don't know. We give these names to these mosquitoes. We have spent so little time understanding theirinating. Now, we don't know. We give these names to these mosquitoes.

We have spent so little time understanding their ecology. Now, going back to the Arctic, there's 4,000 described species there of insect. 2,000 of them are flies, and quite a lot of them are the mosquitoes. They're really important Arctic pollinators. They exist in regions we don't know. Now, their larvae, There's a lot of them.

And they're really good food. So if you suddenly get rid of a food source for a lot of the higher animals to feed on, you're suddenly having a massive knock-on effect. So we do not know the unintended consequences of eradicating a species. They have looked in areas where cities in the Congo Basin have gradually hit forests. I mean, we've seen what happens when we do that. And the malaria has jumped into these new species. So even if we did eradicate these mosquitoes,

what's to say something isn't going to come in and fill that vacuum? I mean, I would just add, you know, I just completely agree with Erica. I know, shocking. I completely agree with you. I think that there are loads of unintended consequences add you know i just completely agree with erica i know shocking i completely agree with you i just i think that there are loads of unintended consequences for doing such a thing um i mean the there was a mass spraying of ddt to control crop pests and mosquitoes in the in the states in the 50s and that kind of led to a huge environmental problem where DDT went up the food chain into birds and caused a huge devastation in populations and that that led to the environmental movement because that was Rachel Carson who said this is this is a silent spring she wrote a book called Silent Spring

but you know these are really hard questions because controlling populations of mosquitoes does help people survive and so when we use smart technology when we've used different technology that's always backfired the best things that have helped are bed nets and things like that when we've understand the ecology we've said hold on these are night feeders let's give them that let's let's give protective clothing we create a barrier we break that rather than trying to use this kind of massive hand that's going to slam down on population can't you also control it by drinking a lot of gin and tonic i'm trying it does work though doesn't it yeah you know that actually there was a beer created when there was a black fly outbreak in dorset in the 60s but it was really strong it had ginger in and i guess it works if you have enough

and in terms of bats i mean clearly well dave mentioned it of course um covid came into humans from bats we think we think so um in terms of that, is the answer really to limit our interaction as much as possible? Is that the way we're going to prevent future coronaviruses or whatever it may be, jumping species? Well, I think the biggest issue is that when we degrade landscapes, when we chop forests down and turn them into something else, you change the communities of animals that are present in those landscapes. So this could be insects too, right? And, you know, you have these animals which, you know, can survive in these degraded spaces. They invest less in immunity. They reproduce faster because they're kind of more stressed. You know, they have to survive. And it tends to be those species which host these pathogens. it and we can show globally that this is what's happening to our environments which they're becoming more degraded the communities of

animals in them are changing because they're trying to survive and they're more likely to be hosts of these pathogens which are you know jump into humans so the answer is to restore these habitats and make sure that we're living in an environment which is healthy, not just for them, but for us as well. Yeah. We need to kind of get the balance back. We need to. And we have one planet. And if we carry on at the rate we're doing,

we're not going to do... You know, you're seeing it already with species loss of insects and things like that. And it's only taken people now to realise why insects are important. So it was like, you know, save your panda your panda i mean at the end of the day no offense to bats because i do like bats you can get rid of all mammals and it won't have any consequence to the planet some bats can stay okay because of tequila i'll do that right those can stay but if you get rid of insects we

would just fall apart within months and and that's, you know, I want to live with them. I think they're very nice. So we've got to the point now, I suppose, the reason for doing the show was the ultimate message, kill all mammals. I did want to ask one question. We had a question. We thought, you know, often when we speak to scientists,

we speak about a scientist, for example, who studies Mars, and they'd want to go to mars brian blessed famously um wants to go to mars you little bastard yes so we thought we'd ask so you know we talked about the way that bats experience the world insects experience the world and we thought it'd be quite a bizarre question to ask you both if you could so erica first if you could experience the world like any particular insect it's almost like a david cronenberg film if you could become a particular insect what would you what what which insects would you become which fly would you like to be and this is eventually going to be like a version of Stars in Your Eyes. Tonight, I'm going to be Drosophila.

I can't decide. He's either a robber fly or a bee fly. Robber flies, because they're just the most amazing aerial predators out. They're highly venomous. They've got supreme sight. Their flying abilities are amazing. They're hard. They look amazing.

But bee flies, they're really naughty but really good pollinators i mean they're larvae eat baby bees and she's basically got a machine gun well she has a little bum bag which i think you know i've got a covid bottom as i describe it and i quite like you know just laying eggs midair and just hurling them around the garden. I think that's my level of... And Kate, what's the bat with the lifestyle you most envy? I think it might be the hammer-headed fruit bat. So I don't know whether you want to have a look at this online later, but it's got an enormous head.

This is the one that looks like a dog. Yeah, and they have this enormous kind of nose that they go around honking. Honestly, they honk, honk, hon they have this enormous kind of nose that they go around honking. Honestly, they honk, honk, honk like this. And so when the males are attracting females, they gather all into a little, a lek, which is called a lek. And the males are performing for these females that come and go, oh, yeah, amazing. And they do this honking and it's just incredible. Absolutely incredible.

What a lifestyle to go around with this massive... I'm not the image now, but basically you two with your different life. You're down there honking, she's chucking eggs around and eating bees. It's magnificent. Dave, have you... So, Dave, what have you decided? I think the winner is the plant that's parabolic. I think that's better than both bats and flies.

I think that's amazing. I think it's all interesting, but when you say, you know, you shouldn't have a go at the mosquito, it's just doing what it was put on this earth to do, I think a human instinct is to try and swat a fly. So we're just doing what we were put on this earth to do. Well, I think, yeah, we'll throw this to the audience. By the way, let's just have a quick vote

in terms of we're going to do bats and flies. Yeah, well, I don't know how we're going to do it. All right, put your hands up if you support the bats. Ah. See, I've got to say, Brian, for radio, I'd have gone with the making a noise. LAUGHTER Say, Brian, for radio, I'd have gone with the making a noise. You actually, for once, have a point.

Which noise shall we have the audience make? Honking. A honk. If you support the bats, honk... Which bat was it? A hammer-headed fruit bat. Honk like a hammer-headed fruit bat. Honk like a hammerheaded fruit bat. Oh! And if you support the flies, then what, Erica,

what's the fly noise that's... Throw an egg at them. I guess. Oh, it was 50-50. Exactly balanced. Flies and bats. The most successful vote given to the public that's happened in the last ten years.

We also asked the audience a question as well. We wanted to know, would you rather be a bat or a fly? And we would like them to explain why. I think you've got the bat ones, haven't you? Yes, and Dave's got some as well. We wanted to know, would you rather be a bat or a fly? And we would like them to explain why. You've got the bat ones, haven't you? Yes, and Dave's got some as well. Those are the fly ones. So, the first one is from Tim. A fly. Batman is no

superhero, just a rich bloke who thinks he's tough. The fly, on the other hand, starring Jeff Goldblum, is a clear winner, and I totally agree with you. By the way, Erica, just out of interest, how scientifically accurate do you think the metamorphosis of Jeff Goldblum from Brundle into Brundlefly is? Well, actually, I've been asked to review it on that very basis.

And, um... Yeah, this is what I get paid to do. No, honestly, this is... So, the feeding habits changed remarkably. Absolutely brilliant. His sexual appetite increased enormously. Totally on. now honestly this is um so the feeding habits changed remarkably absolutely brilliant his sexual appetite increased enormously totally on it's only at the end when he starts dropping bits off and becoming with that's when i kind of lost it because he would have emerged as a fully formed fly as it were from that stage because he's an adult so i mean you know the behaviour the appetite, all his appetites increased

his drive etc that's really good, morphologically it was a bit poor. And Kate can you review Batman? Well I mean the echolocation didn't really feature until far on on the movie so I mean I do like all the Batman they are pretty nice

but they're not very bat based, I mean the fly is pretty fly based batman has a belt now all the things that we've looked at a little visor as well a bat shaped by visors okay to be honest i feel let down for you not i'm not attacking the bats it just feels like it's a man with a belt i'm going to bring this back to serious science. So Chris Sinclair has said he'd rather be a bat than a fly because nobody ever got their foreskin jammed in a bat. We had to explain that to the producer.

I don't get this one at all. And then we explained puns which is amazing as a producer on Radio 4 to have come across a pun for the first time after 25 years I think you explained that some flies do get things jammed in bats didn't you? the pear shaped ones

Barry you've made a fundamental error here Barry he says a fruit bat has a much healthier diet than excrement to which I think the obvious rejoinder is what about a fruit fly yeah you know you haven't you haven't helped solve the debate have you you've just fired it up again barry some some of us will be reading these as jokes others will merely turn this into a moment of pedantry or footnotes

kath said i'd like to be a bat because my husband says that I have the hearing of one. Someone with the unlikely name of Max Power says, bat because flies tend to get swallowed by old ladies. And then Sandy says, tough call, but it's a bat by a squeak. Well, thank you very much for your jokes and your answers. And thank you very much for your jokes and your answers and thank you very much to our panel, Erica McAllister, Kate Jones and Dave Gorman. Now, next week we're moving from the skies to the seas and exploring the deep oceans.

We'll be asking, what's better, a fish or a sponge? No, we won't, that's cheap. That's the line from Whittenail and I, isn't it? No, Whittenail and I is, are you a sponge or a sponge? No, we won't. That's cheap. That's the line from Whittenail and I, isn't it? No, Whittenail and I is, are you a sponge or a stone? I'd rather be a sea squirt, because they eat their own brains. They do. Sea squirts eat their own brains. Why do you want to be one? Because mine keeps making noises, and I don't like it.

So I'm going to eat my brain and watch Gogglebox or Homes Under the Hammer and just relax. Well, if you've eaten your brain, you can't even watch Home for the Hammer. Oh, yeah, you can. You can. Anyway, so that's what we're going to be looking for. Goodbye. Shock or Seahorse! APPLAUSE In the infinite monkey cage In the infinite monkey cage

Turned out nice again. Hi, I'm Greg Jenner and You're Dead to Me from Radio 4 is back. Yes, we're the comedy show that takes history seriously. And this series, get ready to hear about Frederick the Great of Prussia with Stephen Fry. I'm just thrilled at this history lesson. Learn a fair old amount about an ancient Egyptian queen with Kima Bob. What a vibe.

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