The Infinite Monkey Cage - In Praise of Flies

Episode Date: January 11, 2021

In Praise of FliesBrian Cox and Robin Ince kick off a new series of Infinite Monkey Cage with a look at probably the least revered or liked group of insects, the flies. They are joined by fly sceptic David Baddiel , fly enthusiast and champion Dr Erica McAlister and maggot expert Matthew Cobb to discover why a life without flies would be no life at all. Can Erica and Matthew persuade David to put his fly gun down and learn to love those pesky pests, or is their reputation for being disgusting and annoying justified? What would a planet without flies look like?Producer: Alexandra Feachem

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Hello, I'm Robin Ince. And I'm Brian Cox. Now, today's show is a slightly delayed response to a heckle that I received in 2007. Oh, that's why you remember it specifically, because there was only one heckle. No, it's not. Right, OK. This is rude. This is very rude for the first episode, as far as I'm concerned. I've got one heckle. I was doing a show. It was the first show that I toured about kind of science, my understanding of science. I did a show, two-hour show, talking about Charles Darwin.

I was talking about the fashion sense of the bonobo ape, naked mole rats, all of these different things, black holes. And then after two hours, a man at the back, a very indignant man, just suddenly shouted out, Drosophila, the fruit fly. You've talked about the universe, but why haven't you talked about flies right and so i said the reason that i don't do any observational material about the fruit fly is because due to the rapid nature of its mutations any observation made on a tuesday becomes irrelevant on a friday which kind of went down

okay but i could see the put down yes it did because i have a very niche audience david very niche audience right but i could still tell that the man was flustered afterwards so on a promise i said we'll continue this heckle put down at some point on radio 4 in 2021 so because of that man's heckle this is why today's show is all about fruit flies but not merely fruit flies it is about many many flies as well i'm gonna heckle you robin yeah because it's not merely fruit flies. It is about many, many flies as well. I'm going to heckle you, Robin. Yeah, because it's not a fruit fly. Well, that's exactly why we're doing this show. We're doing this show due to my lack of education

about the nature of flies, right? That was the whole thing. Today's show is called In Praise of Flies, the most maligned of Darwin's endless forms, most beautiful, the underappreciated denizens of the tangled bank, and yet the very foundation of our civilisation. Can I check the foundation of our civilisation?

Is that accurate or is that just the kind of BBC TV documentary Brian talking? I probably got a bit carried away. Today we are joined by a panel of both professional and amateur fly flirters and blue-bottle botherers, and they are... Hello, my name is Erica McAllister, and I'm a senior curator for flies and fleas at the Natural History Museum in London. And I've been asked to say which my favourite fly is, which I can't, but today's favourite fly is the camel botfly.

It lives up the nostril of a camel, and it's called Cephalopena titillata. My name is Matthew Cobb. I'm a professor of zoology at the University of Manchester. And my favourite fly is going to be a Drosophila, but not the one that Robbins Heckler was thinking about. Drosophila sechellia, which is only found on the Seychelles. Or it could be a Dolico podidae, which is a delicate, stilt-legged fly.

Or it could be an acylidae, which is a delicate, stilt-legged fly, or it could be an asylidae, which are the robber flies, the lions of the fly world. I'm David Baddiel, I'm a comedian and writer, and my favourite fly, obviously, is the one that fairly recently found its home on Mike Pence's head. I sort of imagined it, I don't know if anyone else found this, to be the fly at the end of the 1950s original movie of The Fly, which some of you may know is being approached by a spider and saying, help me, help me! Although I imagined the one there was being approached by Donald Trump.

And this is our panel. Erica, can I just start by saying there was something absolutely lovely there that when you actually said what your job is, as you said in the head of flies and fleas, I could actually see you going, it really is my job. There was a beautiful moment, you go, this is really what I do. What is it that first attracted you to flies? So I've always been fascinated by entomology

and I was very lucky I went to the University of Manchester for my undergraduate and there was a lecturer called Dick Askew and Dick is just a legend. He's the king of parasitica. We were at his place in the south of France and he scooped up these insects and he was like, Erica, that eats that and that lays its eggs and that and that does that and I was like, well, that's me, gone.

Because they just, it was just, there's something so, they just get their tarsy in everything they're just so able to get everywhere they can scuba dive they go into space you know they the flies are there at the forefront of trying to do everything so and they look amazing i mean they've grown eyes on the end of stalks the dolly capote is the one that matthew likes their genitalia is extraordinary i mean it's a legendary size so it's just everything about them is just brilliant there's just two things i want i want to ask you i can't move on without asking you about the scuba diving fly

yeah and secondly the extraordinary genitalia can you go into more detail i i made david attenborough blush i feel really bad about this because i was showing him some fly genitalia on my phone and he just looked up at the film crew and went well i feel inadequate and i'm like oh no no no and where'd you go from that because i was like i can't say no i'm sure yours is amazing because i've just even oh god, God. Oh, no. I know. But just before we went on air, you were talking about, for instance, you did an event and afterwards there were a father and son who fasted and you said, just put a dead chicken in your garden and see what happens.

Now, again, this is just not what you normally hear at the end of the kind of Royal Institute Christmas lectures. And don't forget, everyone, just put a chicken carcass in your garden. Leave it. And can you tell us everyone, just put a chicken carcass in your garden. Leave it. And can you tell us what happened? Well, it was brilliant. So we were doing Science Uncovered, and they were like, why is flies amazing?

And I got talking about maggots, because you can't talk about fly without its larval stage. And we were talking about how we can use them for forensics, like they're very good for helping us to know when the body was dumped and things like that. And how in the Tower of the Natural History Museum, because we're not allowed dead bodies in the UK. It's just, you know, a little bit of grave robbing history of ours. So we keep dead pigs.

And so we've got in the towers, we've got some decomposing. Well, we did have some decomposing pigs. And it's amazing when you see the maggot mass developing and stick a thermal, like a thermometer in it. And we had some thermal imaging and see seeing what's going on it's like this is awesome so i was telling this to this little boy and he and his dad went away and got a chicken put it in a dead chicken and put it in a cage i see dead parrots now put it in a cage and they had an old iphone and they filmed it and they did a time lapse uh uh of this video of a decomposing chicken.

What was absolutely amazing is once they get so many maggots, it causes the chicken to rotate. Like a rotisserie chicken? Yeah. You're never going to want one of those. It's the least delectable rotisserie chicken ever. Probably quite similar. But, so he filmed this, and he's brilliant.

He took it to school. He won a school prize for his decomposition video. I mean, his mum's not happy, but, you know, there's a little entomologist there. I thought it was fascinating. I think it's the speed with which maggots will devour dead bodies is absolutely remarkable. There are videos of elephants that have died

and within two weeks it's all gone. It's all been taken away. The maggots, mainly maggots, will just swarm all over it. They're the first to turn up and they're the last to leave. So you've got the pyophyllids, like the bone skippers, who come the last ones. They're the ones who live in the cheese. Have you ever...

Yeah, yeah, pioffelids, yeah. They're the ones that jump, so they form a little... They grab hold of their tail and then they put on a lot of pressure and they can leap about a metre. I had a project once looking at different kinds of cheese.

I was working in France and we had different kinds of cheese with different kinds of maggots in it. In the old days, that was supposed in France, we had different kinds of cheese with different kinds of maggots in it. In the old days, that was supposed to be very tasty cheese. But it's really dangerous because they're also involved with miases, so they can crawl through your

insides. They live inside your guts. Don't eat that cheese. Kazumizu is called something like that. So you actually ate the cheese, French people used to eat that cheese with live flies in them. Is that what you said? Yeah, yeah.

When was this? You still do it. You still do it. Really? Yeah. If you go to Corsica and you go out into the hills, they'll say, I've got some good stuff here. Because you're not supposed to eat it under EU regulations

because, you know, it's not nice. It's one of the main reasons for Brexit. This is brilliant because we can have it now i thought my i saw michael gove say that the other day yeah it's one of the great benefits the great benefit of brexit will be eating maggots and cheese yeah if anyone has ever you know complained that this show is not educational already within five minutes people have learned it's best not to eat things if there are living things crawling in it and around it and that that alone is any as good as any public information film involving a frisbee but matthew um you're a professor of zoology so that covers the whole

range of living things i suppose but um maggots in particular have been central to your academic career haven't they? Yeah, I mean, I'm a bit of a fraud. I'm not really a zoologist, but I do know about maggots or one kind of maggot because I'm a research scientist. So I've been focused on Drosophila, those things that cause the heckle, which are not fruit flies, despite what people call them. People have tried to stop them calling them fruit flies and it hasn't

succeeded. But anyway, so these are the things that have been used to study genetics and to, we probably know more about this organism, this animal, than any other animal in the world, apart from perhaps C. elegans, the worm, and that's only got about a thousand cells. So we know everything about its life cycle, about its genes. It's been studied for over a century now. And I've been studying the maggot, in particular, its sense of smell. It's got just 21 smell cells. And because it's Drosophila, we can fool around with its genetics.

And I can make a maggot with just one functioning smell cell in its nose. And it will wriggle towards the smell. Or we can record from that electrode and find out what's going on inside a smell cell in its nose and it will wriggle towards the smell or we can record from that electrode and find out what's going on inside a smell cell david what was it about uh this particular panel that drove you you know i know you were very very keen to appear on a panel talking about flies for 30 minutes yeah i don't know if you know robin but there's not a lot of work out there for comedians at the moment uh so that was it really um you know live work's dried up i had to go to flies uh but nonetheless uh i am quite interested in flies i like i do like the

fly the movie very much uh but one thing i do think about flies culturally because obviously i'm learning about them you know scientifically here i don't know much about them but culturally they're very low even for insects do you know what i mean like people sort of like bees but a bee is just a fly with a knife basically isn't it like a bee is worse in many ways for the than a fly spiders which i hate but you know spiders at least got a superhero you know spider spiders at least have got a superhero, you know, Spider-Man. And also people say, oh, he wouldn't hurt a fly. But people hurt flies. I've never met anyone who wouldn't hurt a fly. My wife, who is the nicest person in the world,

she will carry a spider out into the garden. She'll swat a fly, definitely. So I want to know why flies, why are they so much the villains of the insect world? So I think they haven't always been they were awarded for bravery by the egyptians so we did appreciate i thought it was going to be like a pride of britain award that i missed but i guess there's there's one or two species that are so amphithilic they so love humans that they're the ones we always hang around with and they're the ones that vomit eat feces or transmit diseases so that's a bad brand image isn't that is bad

but that's like oh 150 of the 180 or so thousand described species so we have tended to like just focus on the bad ones but not like all the ones. Even the bad ones are quite good as well, because that housefly that vomits is also a really important pollinator. So generally, they've had really poor press. And you're right. Yeah, they have. Bees, they are stabbing you with their genitalia. It's also genitals, is it?

Yeah, it's the female genitals. Do they make David Attenborough feel inadequate? Oh, they're female genitals. Female genitals. They make David Attenborough feel inadequate. I'm they're female genitals. Female genitals. They make David Attenborough feel inadequate. I'm not going to say who they might make feel inadequate. I'm going to get cancelled for that. So I didn't know that.

I thought it was just... I didn't know the sting was a sexual organ. I'm sorry, I don't want to move on to bees. That would be terrible. Sting is a modified ovipositor. So if you've... He wasn't when he was in the police. I'll tell you that.

How dare you! That's it, I'm out of here. That joke will do for me. Joking aside, what that means is if you find a male hornet or wasp, it can't sting you. On the other hand, it's quite difficult to know which are the males and which are the females, so don't try picking a hornet up unless you're very confident. Oh, I didn't know that. I didn't know that.

OK, so male hornets can't sting you. So the only time you've ever been pierced by a fly, a mosquito, that's a female. So only all of the flies, apart from the tetsis, are all the females are the bloodsuckers. The males are all vegetarian. Right, because I think I have been bitten by a fly once. You've never been bitten by a fly.

You may have been pierced, shredded, sucked, maimed, but you can't be bitten because they don't have jaws. What fly was it? Do you know? You know, I didn't ask. Foolish of me. It was on my back and it was a fly because I saw it buzz. By the way, I want to ask later why they buzz. Because I would have thought that evolutionaryism is a bad thing because it alerts you to the fact they're there

and you swap them more easily. Well, in fact, bot flies, because they're so fat and heavy, because they're such loud buzzers, they will catch a mosquito and lay their eggs on a mosquito. So when the mosquito feeds off you, the bot fly egg then drops off and the larvae then crawls through the hole. So not only can you have a bot fly maggot,

you get dengue at the same time, which is quite fun. Somebody's going, ugh. Must be said that amongst entomologists, rearing a bot fly is a great thing. People want to, you know, they're very happy if they go to the tropics and they get one of these maggots living underneath them. They then want to rear it and to get the fly coming out.

No, I say this, I've popped one out of my friend's head. So, no, no, he's a primatologist, so he was very, so we're in costa rica and we're in the jungle no i'm sorry but that that so people are disgusted by i think but then you're meant to people are not gonna be oh no don't worry he was a primatologist that doesn't seem to stop the disgust of you popping a thing out of someone's head merely due to their their job well he should have been like you know it's a jungle get used to it but he should have been like, you know, it's a jungle. Get used to it. But he looks at primates and, you know. But he was in his head.

And what's quite fascinating, because they can't burrow down at that point, obviously because of the skull, so it grows across. So I was able to watch it developing, which was fab. But at night, when it's all quiet, you can hear it eating. And... LAUGHTER Well done, Erica can hear it eating. And, um... LAUGHTER Well done, Erica, by the way.

137 shows, and already we've had more urrs than we've had in every single one of all of the 100. Because it's this image, though, of the crawling across, like some kind of underskin comb-over happening. Seriously, that's not the bad thing. It's because maggots feed one end, defecate the other end. Obviously, obviously they do. I don't think you should go, er, about that.

Humans do that too. Here's news for you. We all do that. Just while we're on this subject, Erica, I think in your book you describe the most gruesome of all are probably the forids. I love the forids, are probably the forids. I love the forids, the horrid forids. They're arguably the most ecologically diverse family of animals on the planet.

So these are the ones that they go to the coffins. They're the coffin scuttlers. The females can rip her wings off and she will dig down six feet to find a body. So they're the last ones to turn up at sea. they also you name it they do it and one of my favorites are they the ant decapitators so i this is just brilliant so her her genitalia and she's got really obsessed yes it's very important yeah um i'm gonna leave it out there because I will talk about genitalia a lot. It's something my family have come to terms with. This is such...

These specific entomology magazines with readers' flies pages. This is... I tell you, the internet has made pornography go mad. But she's got this genitalia that looks like a tin opener, you know, those campsite ones. She darts down to get to the ant's back and at the weakness on its back, she will basically pierce through, insert her egg, the larvae hatches, crawls through the thorax of the ant, into the head. It then eats out the head cavity for the next two weeks and then releases, some

of them release an enzyme and then the head comes off so they've decapitated it and they pupate in their little head capsule so it's a brilliant little protective environment and then bish out pops that is amazing it is amazing that is amazing that is incredible yeah and the ants don't like the ants can hear them around and they get very upset they may be able to smell the forage flies coming around. You can go on YouTube, you'll find videos of the flies buzzing around. The ants know that this might be about to happen. Yeah, and so they're trying to get them away and all the rest of it.

They haven't got rolled up newspapers, so it doesn't work. But the thing is, these ants are bad ants. So the flies are actually doing everyone a favour because a lot of them are the fire ants. So they've made it to North America. They've gone aboard ships. They got into North America and there's no natural predator for them.

So we've gone back to South America, find these flies and they only specifically attack these imported ants. And we have no anti-venoms for ants. So it's really, really useful that we're getting rid of them. Matthew, we're going to try and just briefly, Well, it might lead to something lurid as well. But in terms of genetics, this seems to be that the the importance of flies in research, in understanding not not merely flies, but so many different living things. Yeah. So the fly, the fly. I mean, Eric will get cross about this,

this is what scientists, they talk about the fly, by which we mean Drosophila melanogaster, which is the fly that was used by Thomas Hunt Morgan at the beginning of the 20th century to try and understand how, well, if genetics worked, it had kind of been rediscovered following Mendel's work at the beginning of the 20th century and Morgan was trying to work out was there such a thing could you get this transmission of characters and he eventually found a white-eyed fly most flies that he studied had little red eyes and this one had white eyes and they kept it and bred from it and they discovered that only the males had white eyes or they were able to show that it was

on the x chromosome which determines the sex of the the fly so very soon within about five eight years morgan and his phd students were basically able to show that genes are on chromosomes that they're ordered in a particular way and you can make a chromosomal map of where the position of genes are and later on they showed that you could create mutations using X-rays. So basically, all of classical genetics was established using Drosophila. And what that led to is a whole community of people who have found their own particular gene, and they often give them rather strange names. So there's a fly, a mutant that doesn't have genitals,

which is called Ken and Barbie. You've come back to that, everybody. Yeah, that's all there is, mate, I tell you. There's the mutant that got me interested in Drosophila, couldn't learn, stupid, so they called it Dunce. And one I've just discovered, there's a mutation called Cleopatra, which is lethal. It kills the fly if it is in the presence of another gene, which is called ASP or ASP. So they're a sophisticated bunch. It's not all genitalia.

Would it be right to say that scientifically speaking, in terms of genetics, you're not really interested in the fly at all. It's the simplicity of the organism that is the important thing. Yeah, that was the starting point. I'm glad to say that people are now interested in flies and Drosophila as an organism. I mean, for most of the 20th century, nobody knew much of it. Where do they go in the winter? Do you know where they come?

I mean, they disappear. They must overwinter, but they're all in your bins these are the flies that come ballooning out of your your vegetable waste bin in kind of august and september and then they've all gone so they're they're overwintering somewhere but because they're so small which is the really bad side of them they are absolutely tiny it's very difficult to study what they do in the wild um can i ask a question which is in in the fly in the jeff goldblum remake this is actually gonna have a serious point there's a brilliant speech in that just before he turns into a complete kind of insectoid monster he's just still a tiny bit human and he does this incredible speech where he says

insects don't have politics they're very brutal no, no compassion, no compromise. I'd like to become the first insect politician. It's an odd speech because it implies that politicians do have compassion and compromise, which they don't anymore, but maybe they did in 1985. But my point is, do flies have any kind of community? Because obviously ants do and bees do. But I think of flies, apart from when they're all on a carcass, as solitary creatures. I tend to see one in my room that I'm chasing all night or whatever, but do they have any kind of communal thing? Do they work together at all?

Yeah, there's some flies that are not quite eusocial, but they're getting there. It's the New Zealand batfly, and they live together in massive family units and they groom each other, and the larvae groom the adults and things like that. So we're seeing levels of that. But you get a lot of flies.

In the UK, we've got cluster flies. They're the ones who are all coiled up together in your houses over winter. So they all come together into this little thing. So there are kind of examples of them doing it. They're not not same level of eusociality that you get in the bees and the ants and things like that but there's definitely little things going on yeah maggots work together and so drosophila maggots want there to be lots of other maggots they're churning up the food so you get yeast coming in so they can eat it so

that's really what they're interested in so if you get one fly when the female lays her eggs on a fruit she will put in a compound a kind of pheromone that attracts other females and gets them to lay eggs and so you've got lots and lots of these flies work maggots eventually working away at the food but if you're a carnivorous maggot if you're eating food then you don't want to come and lay an egg so the females put in a pheromone which says stay away i've just laid some eggs because if somebody else comes along and lays eggs they'll get eaten by the maggots are already there and cats can smell this you've all got cats if you have a fly that lays eggs on the cat food you'd left out the flies cats won't eat it because they can smell what's in that stuff.

So sometimes the maggots are actually working together and they need to be lots and lots of them to be successful. Is there some kind of, following on from David's question, is there some kind of hierarchy of insect intelligence in a way? I mean, I know colloquially we tend to think of bees as being rather clever because they live in a hive and they interact together. The same with ants and termites. You know, they design these wonderful things with air conditioning and they're quite remarkable structures.

So is there a sense in which, you know, I want to say flies are stupid and bees are clever. But is there any sense in which there's a hierarchy of intellectual capacity? To be fair, bees are clever, really. Honey bees, right? They come back, they go forth. Most of the females, they have a really miserable life, OK? They have to work all the time. And even when they retire from going to foraging for honey,

they become nursery, they have to look after the future maggots. So I think that's a really dull life. Whereas flies, they're very much more an individual. They go out, they do things their own time. They don't have to... I love how partisan Erica is about flies. It's like all other insects can piss off.

I love flies. I'm just saying. I think it's about time we stood up for flies. Yeah, well I agree with that but it is fair to say that bees are pretty smart and they can learn concepts of triangularity, for example. Now, I don't think anybody's fair to say that bees are pretty smart and they can learn concepts of triangularity for example now i don't think anybody's tried to do that well flies but they you've probably seen

those those experiments from queen mary college london where they can learn how to play football bumblebees will watch each other i went to see how to play football i haven't seen that can you can you tell me about that because you're not allowed into normal games at the moment, so I might go and watch that. Well, they trained them, so the bees had to move a little ball and put it into a little socket. To be honest, it was a bit like bumblebee golf. It had to go into a hole. And then they got a droplet of sugar, so they were very happy.

And the amazing thing was that if another bee just watched them doing that, they could then go and do it straight away so but they had observational learning and although flies do watch each other and even maggots there's evidence that maggots watch what each other are doing i'm not sure they have quite that ability to learn that social learning that bees do but my bet is nobody's tried to teach a fly to play football so maybe they can can i just interrupt and show you something which i think might upset erica but it's a i didn't just buy this for this show it's a real thing that i happen to own i know this won't work very well on the

radio but i'm showing you this is horrible it's called a bug assault and it is a gun that shoots salt grains to kill flies, primarily flies. And it does actually work as far as I can make out, although I've never actually hit a fly because they move too far. Well, there you go, I think. So it doesn't work. But you can buy this. It's from America, and basically it's for people who think,

well, I'm going to work my way up to some terrible ice fall shooting, but I'm going to start with flies. And I got this and I'll be honest with you it brought out the worst in me it brought out a sort of hunter instinct in me because I did go out in the garden and shoot spiders which was terrible because they just sit there like sort of

terrible trophy hunting but I wondered if the various ways that we have established sort of killing flies I know it's upsetting for you Erica but what's the best way of doing it? Is it the blue Like the ways, the various ways that we have established of sort of killing flies. Like, I know it's upsetting for you, Erica, but what's the best way of doing it?

Is it the blue light? Is it the swatter? Is it the bug assault? Or the spray? No, no, no. The way flies, if you want to catch fly and release it, not kill it, go slowly. Oh, really? Yeah, because they see quite differently.

And that, to them, if you go fast, that's just normal speed. We're on the radio, Erica, so when you say that... Oh, yeah, sorry. The part of the audience know you're showing us if you're getting sauce. If you try and splat a fly, you think you're going quite fast. To them, that's our speed. That's like my mother moving around the house speed. So I know that I'm going to be able to run away from it.

So if you want to catch a fly go really slowly because they don't perceive that as movement as such so you can give gently up and then release it I only like killing for science so unless you donated it to the museum please don't go around killing them that sounded like a horror film

just the two things we've seen which is we've now heard you say killing for science which is definitely what you'd see on the six o'clock news when we find out what... Yeah, maybe I should rephrase that. And then David pulling out this gun, which is kind of this fire salt, you know, when did you become a murderer?

Well, it all just started with some light seasoning and then one thing led to another. I mean, this is... Yeah. I mean, Nigella Lawson, you should watch out for her because she uses cayenne pepper and all sorts. I just want to go back on something a little bit before, which was, does the planet change?

If you remove, you know, in terms of, you've mentioned a few times certain functions, certain things that, you know, are so necessary for flies. So how do, a planet without flies, how does that planet change in terms of the biosphere? It's very smelly. A lot of them eat decomposing matter, be it dead bodies or faeces.

So if you get rid of the flies, you are going to be swinging around in a lot of faeces. Because, you know, what was it? We worked out that there's 9 billion people on the planet and each person defecates one kilogram of faeces because you know what was it we worked out that there's nine billion so nine billion people on the planet and each person defecates one kilogram of faeces a day that's a lot of faeces that builds up really quickly and that's just us elephants they poo a lot although there's not many of them but everything is pooing and you're kind of the flies are there now the dead bodies and it's not just like animal dead bodies,

you've got decomposing trees and all of that. So you gain, you've got this huge community that the flies are converting the energy and breaking down the larger bits of materials, the smaller bits. In the UK, 40% of our flies, their larval stages live in water, and they're breaking down all of the large organic matter and smaller organic matter. So we would become quite choked to start with without the flies. water and they're breaking down all of the large organic matter in smaller organic matter so we would become quite choked to start with without the flies but we wouldn't have most of our pollinators

uh because they're flies chocolate is pollinated by flies you mean cocoa cocoa beans are pollinated but it's so so complicated inside it needs very very very tiny flies to get in and we know there's about 17 pollinators of cocoa of which 15 of them are these flies in the family of biting midges so every time you get bitten by a midge don't curse that family because the rest of them are pollinating i went to scotland for my holidays because you can't go anywhere else now and uh what there was there i didn't know this there's a thing that people sometimes talk about which is a sort of uh old eureka moment i don't know if you've ever heard of this where basically everyone else seems to know this

uh but i didn't and i didn't know that there are midges in the highlands right and and so I go there and I had to buy the most ridiculous hat that anyone's ever bought. Basically, a thing that Australians would say, what have you got on? It's like a sort of hat with a black widow's, sort of Spanish widow's net in front of it. And I had to wear that. And, you know, people just laughed at me, obviously.

But why are there so many midges in Scotland? I don't know. There's a lot of things that they can live off. So they've got a lot of big mammals running around. So Canada's absolutely, again, because of all the moose, you've got all of those. It's interesting, they've looked into it. They've never totally exsanguinated a mammal,

which is quite fun. They have done some floods in Texas. There have been so many blood-sucking insects that they've killed cows, which is quite fun they have done and the floods in texas they've been so many blood-sucking insects that they've killed cows which i quite like no one's killed a human yet blood not directly no they try to give you a nasty disease but they won't you you're not going to end up a husk with loads and loads of midges on outside you apart from on your face where you've got your mantilla or whatever it's called righting you. OK, thank heavens. So, you know, what you don't want to do in Scotland is

go out wandering in the nude because you will get bitten everywhere. Well, I was going to just get one final question to both of you, Erica and Matthew, is what can we learn from flies? Maybe start with Erica. What can we learn that is...

I mean, Professor Crap, which is my favourite professor's name at the moment, from flies maybe start with erica what what can we learn that is of i mean the professor crap which is my favorite professor's name at the moment and imperial he's looking at hoverflies because he's trying to understand what's going on from their vision to their neurological response to their flight response because he's working on supercomputers and how they can use this in aviation so he's looking at that but then there's also people looking at mosquito mouthparts for smart needles because they can flex underneath the skin so the idea of this mouthpart being able to move around we can use it as a needle for for medicine plus also because when the mouthpart penetrates your skin it will vibrate so it's like a pneumatic drill so it's able to pierce your skin without you noticing.

So most people don't realise they're being bitten or sucked by a fly because of this. So again, there's all sorts of mechanical things we can learn. There's the genetics we can learn, behaviour, and ecological and, you know, flies go in... We've been sending them up in space for what, 70 years now, basically. So there's so much we can know about them or we can learn about them to help us learn about ourselves and the environment we're in. Matthew?

Well, simple representations of quite complicated things in a simple organism is going to carry on being very fruitful. And the thing that i'm particularly interested in is how nervous systems work and so there are colleagues around the world who for the last 10 years have been making the wiring diagram of a maggot brain just one because every maggot's a bit different and they it's about 10 000 12 000 neurons and in the end still haven't got there they will have the complete wiring diagram and then even further down the line than that we will be able to model that in a computer and get insights into how nervous systems function so i think what you've got to remember is

because they're simple but they've still got great similarities with us we will be able to get insights into things that are important for us and for the whole of the animal kingdom by looking at these apparently humble and simple creatures one thing i we haven't talked about of course is that flies have ended up in jokes there's a very classical joke uh which is way to way to jokes where flies end up what's this fly doing in my looks like the breaststroke so there's enormous amount of jokes with flies in them but my original point was that flies aren't liked very much and i found myself just before i started this program looking at a series of fly jokes and it was a whole lovely website about all these funny jokes

about flies and then right at the end it said but but all joking aside, flies can be dangerous vectors of disease. And I thought, I wouldn't open with that. So can I just make one more comment that I think is always rather amusing. And when you're sitting in a pub and you've got that fly flying around your glass of wine or your pint of nutty ale. It'll be a Drosophila.

It'll be a Drosophila. Drosophila are known not only for their amazing genetics, but because they have mega sperm. Okay? And the fly, it's... I feel inadequate. I have to finish. Oh, you will.

You will. Their sperm is about a thousand times bigger than yours. I haven't measured... There's really no need for this. Well, you keep making it personal. So, Drosophila, the Melanogaster, it's a three millimetre long fly.

Its sperm is about one millimetre. It's amazing. But it's not as good as the biggest sperm, which is in Berfurca, the Drosophila berfurca, whose sperm is 5.8 centimetres long, which is massive. It's huge. But they only have a few and they don't have teenage years. But their sperm is bigger than they are.

Yeah, it's massively round up. Round up. Yeah, and they've kind of got a pea shooter as a genitalia where they, out it comes. But one of the last... Why? Why is it that way? A sperm competition. So she's trying to kill it as much as possible

and his sperm keeps evolving to be bigger and bigger and bigger as she makes it more and more complicated. Plus he's fighting... That sperm is fighting other sperm that's already in there and they found that the longer the sperm, it's easier to push out other sperm. And now, yet again, David Attenborough's walked over to his radio and going, she's done it again.

Oh, God. That's the end of the week for me. Two knighthoods, but not very big sperm. But one of the last things that you do, one of the last things that flies do is they will, so if there's a female and she's pregnant, because some flies do carry larvae, so she is pregnant, if she's in a last-ditch situation and she just lets do carry larvae, so she is pregnant, if she's in a last-ditch situation, she just lets all the

larvae go, all the eggs go. And some males just let all the sperm go as well. So when it falls into your pint or your drink, and it's dying, one of the last things it might be doing is ejaculating into your nutty owl. Which is just a nice thought.

Please can we end the programme now? Please, Brian. I have to eat dinner. This is going to be such an interesting edit for our producer because, I mean, there definitely will be, much like the Derek and Clive albums, there will be this kind of, you know, secret recordings going out of that which Radio 4...

Well, it is going out at 4.30. I'm just not sure about the nutty ale bit. So, anyway, next week's show, we should say, keeping thematically with how we've started this week's show, next week's show is an answer to a heckle that Brian received in a lecture about special relativity. It's the one that every performance-based physicist has probably received at some point, which is, obviously,

what about the astronaut's paradox? Well, the full heckle was given the fact that moving clocks run slow and all inertial frames are equivalent surely both astronauts age more slowly hence a paradox the resolution of course as you know robin and david knows this as well is that the symmetry is broken because if the astronauts wish to meet up at some point in the future and compare their ages then one of them has to move into a different inertial frame, and this one will be younger. But it turned out that Heckler was just wanting to know, really, if it was possible to take Britain back to the 1970s. In relativity, that isn't possible. In politics, it turns out it is.

Obviously, Brian came back with, I remember when I had my first drink, too, so it was all absolutely fine. Thank you so much for listening to the show and thank you very much to our fantastic guests, Matthew Cobb, Erica McAllister and David Baddiel and hopefully we will see you again next week. Bye-bye. Bye.

Thank you. Turned out nice again. In the infinite monkey cage. Till now, nice again. and just five bucks with a small coffee all day long. Taxes extra at participating Wendy's until May 5th. Terms and conditions apply. In our new podcast, Nature Answers, rural stories from a changing planet, we are traveling with you to Uganda and Ghana

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