Social Insects and Locust-Inspired Car Safety

18 June 2006
Presented by Chris Smith, Helen Scales


Scratching the itch of curiosity this week is William Foster, who will be talking about the evolution of social insects and his quest for social beetles in Thailand, Claire Rind flies in the face of current car safety technologies by using knowledge of collision avoidance in locusts, Matt Shardlow discusses how man-made wastelands can be a haven for rare invertebrates, and Derek Thorne joins Ed Turner in the garden to discover how to make pitfall traps.

In this episode

To Biodegrade, Or 'rot' To Biodegrade?

Researcher Adam Gusse and his colleagues at the University of Wisconsin have found a fungus capable of rotting the previously un-rottable - compounds called phenolic resins (PRs), the plastics used in the trims on car bodies, air filter housings and other heavy-duty automotive parts. They're made by heating phenol and formaldehyde (formalin) to high temperatures in the presence of catalysts which cause the molecules to link together in a three-dimensional lattice that is hard to break. But therein lies their weakness - these compounds, which were previously thought to be non-biodegradable, closely resemble the natural substance lignin, the hard part of wood. Since lignin is a popular food source for fungi, the researchers wondered whether the cocktail of lignin-busting enzymes produced by "white-rot" fungi might also be able to break down these phenolic resins. They incubated cultures of fungi with the plastic and looked for signs of degradation. In tests on 11 fungal isolates they found one strain, called Phanerochaete chryosporium, which was capable of digesting the phenolic resins. Under an electron microscope samples of the resins showed pits where they had been eroded by the fungal digestive juices. This suggests that it might be possible to use this technology to recycle the millions of tons of phenolic resins produced each year instead of dumping them in landfills.

Simply Hair-raising

A study amongst Welsh school children, published in the journal Archives of Disease in Childhood, has found that four out of five headlice are now resistant to treatments, such as permethrin and the organophosate malathion, which are traditionally used to eradicate them. The researchers combed their way through the heads of 300,000 school children from 31 schools. They then tested samples of the lice they collected to measure their resistance to treatment, including the levels of enzymes such as glutathione transferases, mono-oxygenases and esterases. Of 316 lice tested, 80% were resistant to the standard treatments. Healthcare workers in Wales are now presumably scratching their heads as they try to decide what to do about the problem. Although the study was conducted in Wales, the same treatments are used almost universally for headlice, so it's likely that what's true for Wales is going to be true elsewhere too. Thankfully help might be at hand in the form of newer silicone-based lotions, to which the lice are reliably sensitive.

A ladybird

Catching Insects with Pitfall Traps

Derek - Hello there and this week we've come to the Museum of Zoology at the University of Cambridge for National Insect Week. Of course, we are now in National Insect Week so we're all very excited about the science experiment we're going to do this week because we're going to be catching insects. And we're doing this with the help of one chap who's come to help us out. Would you please introduce yourself for us.

Ed - Hi my name's Ed Turner and I work at the zoology department here in Cambridge and also with the Wildlife Trusts.

Derek - Ok and I gather you set up some experiments to catch insects for us?

Ed - Yes, what we've done here is set up some pitfall traps to catch some insects.

Derek - Fantastic. We've also got some volunteers who have come along to help us out. So guys, could you give me your names and what school you're from?

Sam - Hi I'm Sam from the Perse.

Luke - I'm Luke, also from the Perse.

Derek - So do you guys like insects?

Sam - I've loved them since I was very very little.

Derek - That's absolutely fantastic. And yourself?

Luke - Yeah I like insects too.

Derek - So Ed, what we need to know is how to make these traps, because people at home can do this as well and they've been encouraged to do this over the past week. What do you have to do?

Ed - Well it's very very easy. All you need are some plastic cups and you need to find a patch in your garden where you can safely dig. Don'' dig up the middle of your lawn or anything like that. Just dig a small hole, put the cup in and make sure the surface of it is completely flat with the soil, so that any insects walking along can easily walk into it. What you could also do is put half a bucket over the top of it to protect it from the rain.

Derek - Obviously people might be thinking that they don't want to cut up their bucket at home. Is there anything else they can use to protect it?

Ed - Yes, absolutely anything. An old ice cream carton. Anything like that really.

Derek - And suspending it above the cup to protect it from the rain. How can you do that?

Ed - Well what I've done is use some bamboo poles but you can use anything at all to hold it off the surface.

Derek - Now we're actually at the New Museum's Site in Cambridge and we've set up some pitfall traps already, but what are the kinds of places we can set them up in?

Ed - What I've done here is to actually put some traps in the border in the loose soil. I've also put some beneath a hedge and I've put some into the lawns as well. I've had the permission of the gardeners here in zoology. You could do that if you're careful but you should ask your parents first.

Derek - Yes we must be careful to make sure that no-one decimates their parents' lovely lawn here. So just to recap what Ed said there, we've got four pitfall traps here in slightly different positions. One of the is on the lawn itself and the others are in the soil. One of them is in the shade, one of them is quite far away from the border of the lawn and one of them is close to that border. So why don't you have a go at home? Try and find out the different places you can put the traps and see what you get. And Sam and Luke are very keen to find out what's in these pitfall traps, but we're not going to find out yet. We're going to find out later in the show. Sam, what do you think we might have go tin some of these pitfall traps?

Sam - In the lighter ones you may find smaller insects than in the shade, because the shade gives them more protection.

Derek - Sounds like we have an expert here. Ed is nodding very impressed over there. And Luke, what do you think?

Luke - We might get some grasshoppers or flies or something.

Derek - Ok, and we will see all about that very soon. We encourage you to have a go at this at home, and if over the past week you've been having a go at this, then please tell us what you've found. If you're emailing, why not send us a picture. We will be back here at the Museum of Zoology very soon. Please do join us then and back to the studio.


Derek - Hello there once again to the Museum of Zoology at Cambridge University and we are here with the result of our pitfall traps which Ed Turner from the Museum of Zoology and the Wildlife Trusts has set up for us. Sam and Luke are ready with their results so why don't we have a look. Ed, would you like to instruct Sam firstly on what to do with the cup which we've just taken out of its position in the garden?

Ed - We've got lots of stuff here so we need to pour it right in the middle. We've got a white tray here so we can easily see the insects we've got. We need to pour it right in the middle and things are already hopping out as we do that.

Derek - They are insects are they, Ed?

Ed - Well they're not really insects. They're very primitive insects. They've got six legs but they're not actually insects. They're called non-insect hexapods.

Derek - Ok, well tell me a bit about them then. They look to me as though they're about 3 or 4 millimetres long. They're crawling round a bit like ants but with longer antennae. What else can you say?

Ed - Well we can look at them and we've got some hand lenses here, which you can get from shops quite easily. They're very velvety, and I think Sam's just having a look now.

Derek - Tell us about it Sam. What can you see with the magnifying glass?

Sam - They're quite hairy and they've got a sort of stripe through the middle where there's a colour change.

Derek - And also, what are they doing?

Sam - They seem to be escaping. Occasionally they'll jump but they won't go too far.

Derek - What's all the jumping about?

Ed - Well that gives you a clue to their name. They're actually called springtails. They have a spring at the end of their tails, which is a little structure that looks a bit like an arm. They can straighten it very fast and will propel them into the air, so it's an escape response. The reason is that these things are eaten by nearly everything, so that's why they're a bit nervous and twitchy animals. Everything's trying to munch them.

Derek - So Luke, how about you pour some of one of your cups out onto on eof the white trays that we've got here. And Luke, where was that one from in the garden?

Luke - That was from the lawn.

Derek - So that was actually in the grass. What have we got here?

Luke - We've got a woodlouse, which is curling up.

Derek - Yes, I think I can identify a woodlouse as well. Ed, what can you say about that?

Ed - Well that's another very interesting response to predation here to escape predators and things that are trying to eat it. It's a pill woodlouse, so its response is to curl up a little bit like an armadillo and protect itself from predators.

Derek - Ok, so these things think that we are predators, do they?

Ed - Yes absolutely. They're in fear of their lives but of course they're not going to be harmed today; they're going to be put back afterwards.

Derek - Let's have a look at a third cup then. Luke, have you got another one there?

Luke - Yes, it was in the shade in the soil.

Derek - Ok let's pour that out then and see what you've got. What can you see there, Sam?

Sam - I think there's a young devil's coach horse.

Derek - Ok and describe that for me.

Sam - It's long and black. It's got six legs like your average insect but it's long.

Derek - Sounds like we have a real expert here. Ed. What do you say?

Ed - Yes he's absolutely right. It's not a young one but a different species. With insects the larvae are a bit like grubs with beetles. So it's a bit like a beetle. And you're quite right: it's a devil's coach horse, it's a rove beetle. Unlike most beetles that have these two big hardened wings cases, if you think of ladybirds, rove beetles actually have very tiny wing cases. The reason is that they can then move very easily between the soil or in cracks and often hunt for smaller insects, such as these collembolans, these springtails we've already seen.

Derek - One thing that occurred to me when Luke poured out that cup we got from the shady part of the garden is that we got a lot of insects in there. Is that what we would expect?

Ed - Yes, absolutely. What we've got here is lots of animals that are living around in the moist ground and in the mud and they don't like to dry out too much. This is maybe why we're getting more insects.

Derek - I am very impressed with the stuff we found here and delighted as well that it all did turn out fine. So Sam, what did you think of our list of insects here?

Sam - I think we definitely got more insects nearer the shade.

Derek - Yeah and you guys predicted that, so I can't take any credit for that. Well done to you. And Luke, how did you like the experiment that we've done?

Luke - Yeah it was good. We got lots of different insects, different types.

Derek - I think hopefully you at home will have heard that it's very easy to do, the pitfall traps that we've made here. You should do it at home and tell us what you find. And Ed, if people would like to get some more information on what they've found, what else can they do?

Ed - Well they can come along to National Insect Week at the Department of Zoology on the 24th and bring any insects that they can't identify themselves. We've got an Ask the Entomologist section, so an ask the insects expert section, so bring along all your stuff and we'll do our best to identify it for you.

Derek - And this is all at the Museum of Zoology on the New Museum's site, and maybe you'll even see the pitfall traps we set up here. Thank you very much to Luke and Sam and to Ed for setting up th experiment. I hope you have a very fun insect week looking for insects where you are. We'll be back next week and until then, back to the studio.

- Locust-inspired Car Safety

The Naked Scientists spoke to Dr Claire Rind, University of Newcastle-Upon-Tyne

Locust-inspired Car Safety
with Dr Claire Rind, University of Newcastle-Upon-Tyne

Chris - When we say compound eye, how does the insect actually process the light coming in? It's got loads of images of the world coming in at once. That must take a lot of processing.

Claire - It does take a lot of processing but that isn't the way the insect looks at it. They don't have thousands of complete images. Their whole image of the world is pixelated and broken up. Every little lens looks out at a particular region in space and then it just has to put together all the information from that particular region in space. There is some beautifully engineered circuitry and it's repeated many times over the eye.

Chris - You actually won an Ignobel Prize for showing episodes of Star Wars to locusts. Why?

Claire - Because I could!

Chris - Who was funding this research?!

Claire - The BBSRC. Star Wars had a huge array of visual scenes and looming motion, and that's why we chose Star Wars. Looming is when an object is coming straight for you, like a spaceship. The other thing is that they have spaceships moving directly over you. They were coming very close but weren't actually having a collision. So we could test the different responses of the neurones to a near collision and a collision.

Chris - And this is your locusts' anti-bumping device.

Claire - Yes.

Chris - How does that actually work?

Claire - It detects objects which are approaching and expand over the eye. There are circuits that extract those image cues and will give a warning when the system detects very rapidly expanding edges, which are features of objects approaching on a collision course.

Chris - So how could you apply that to the automobile industry, as this is the stance you're taking on this?

Claire - The way we're applying this is that we've got a little silicone chip which is inspired by the insect eye and it has small photocells rather like the cells in the insect eye. The signals are passed through various layers of circuitry, and eventually after much computation, the signals are summed up and a collision warning is issued if there is sufficient evidence for there being an object on a collision course.

Chris - But how is this better than a driver at the wheel of a car anyway? Or are you thinking now of a car that has autopilot or something?

Claire - They could have an autopilot, but at the moment the driver is not very good at reacting quickly enough. This is especially so if a child or something steps out quickly in front of the car and the accident is imminent.

Chris - Say a child steps out but there's a child coming the other way. How does your computer resolve that?

Claire - The most salient features, or the ones that give the biggest responses , would be the ones the system would react to.

Chris - So it would hit the kid and ignore the car coming the other way then.

Claire - No it wouldn't hit the child. That would be the image that was expanding most rapidly over the sensor and the collision alerting system would be switched on by that image. It ignores a lot of other movement, like flow fields, or images flowing back over the sensor. It's specifically looking for an object which is on a collision course. The car coming straight for you will be a problem for you as well!

- In Search of Social Beetles

The Naked Scientists spoke to Dr William Foster, Department of Zoology, University of Cambridge

In Search of Social Beetles
with Dr William Foster, Department of Zoology, University of Cambridge

Chris - One of your interests is in social animals and you're going to be going out to the back of beyond to Thailand soon. Why is that and what is it you're going to find there?

William - We're hoping to look for social behaviour in beetles. Social behaviour in insects is very important because the most successful animals in the world, of all animals, are ants and termites. They're successful because they're social. They're able to have huge colonies and be very well organised. This has evolved rather infrequently; it only appears in ants, bees wasps and termites. We'd like to be able to see whether the largest group of animals in the world, the beetles, whether any of them are social. There's a particular group of beetles there called passalid beetles, and the Americans call them bess beetles. They have quite advanced parental care, that is that the parents look after the young and do things like help the larvae make the pupal case around them. They can't do this themselves and the parents have to push from one side while the larvae push from the other. It's a very elaborate social care. This has been known for a while but no-one has ever studied them very thoroughly. We know there are large colonies of various species in this part of South East Asia and we want to go and find them.

Chris - So when you're mounting an expedition like that, how do you set it all up? What are the steps involved and how much is this going to cost?

William - It doesn't cost all that much. We're doing it with the Natural History Museum in London and they are mainly going to collect beetles and lepidoptera, butterflies and moths, in the area generally. They've done most of the organisation. What is really required I a permit to bring the material out of Thailand. All countries quite correctly don't like people going in and pillaging all their animals. We haven't yet got the permit and the Natural History Museum are still negotiating with the Thai authorities, but we will have that. Otherwise, you just need somewhere to live, nets, tubes and alcohol. That's 80% alcohol in which to put the insects when we've caught them.

Chris - So not for the scientists to drink then?

William - No!

Chris - So going back to these beetles, do we think that the origin of this social behaviour in ants and wasps, evolved from a common ancestor or have they independently evolved to have this interdependence on each other?

William - It's happened independently several times, but not that often. The termites probably had two origins of social behaviour for example, the ants probably only one. Another group that is social are the aphids. You would expect them to be social because they're colonial. They're clonal and all the same genetically. The Portuguese Man of War is also a social animal. It's clonal it's identical and only some of the animals in a Portuguese Man of War that reproduce.

Chris - So is that the same in aphids? Rather than just cloning themselves they will actually have sex?

William - Well only some of them reproduce. Some of them are totally sterile.

Chris - This is green fly, not Portuguese Man of War.

William - Yes, this is green fly. Some of them are just warriors, like there are warrior polyps.

Chris - Is that to distract predators? If you've got fifty million green flies and a couple of them don't actually do anything except sit there eating and being all fat and juicy, if something comes along to eat the green fly it's more likely to pick on one of the sterile ones. That leaves behind the ones that will reproduce and can foster offspring.

William - Well it's more the case that there are soldiers that are heavily armed baby ones that rush around over the colony kicking off parasitic wasps or anything that's trying to eat them.

Chris - There was an interesting story recently where scientists were looking at how plants have their own alert system where they use chemical signals. When a caterpillar or a green fly eats the plant, the plant releases various chemicals that actually attracts predators that eat the animals that are eating the plant.

William - They don't attract predators but parasitoid wasps. They come flying in and lay their eggs on the caterpillars that are eating the plant. It's a relatively recent discovery but it's definitely true and there's lots of good evidence for this now.

Chris - Going back to your Thailand situation, why is it that no-one's ever discovered that there are these social beetles knocking around given the wealth of information you've already told us? These things have this interdependent relationship with each other. They can't reproduce without another's help.

William - People have studied them a little bit. Some work has been done in America. An American school teacher in the 1930s kept them by his bed and watched them doing various things. I suppose there's not much money in them and they're not that important ecologically. They are quite important. They live in wood and break down wood. No-one's really been that interested in the theory; the evolution of social behaviour.

Chris - Isn't there a claim that in the same way Claire is trying to look at locusts to see if we can borrow from biology to make cars safer, people are interested in how ants communicate and signals are passed through colonies to make computers work faster?

William - Yes, indeed. I thin there are lots of analogies one can make with social insect colonies and how to make things like brains and complex systems work. All these colonies work on simple rules that the individuals make. By the accumulation of lots of simple rules and lots of individuals, one can get the emergence of lots of complex properties.

Helen - Going back to your expedition, I presume it's rainforest that you're looking at, how will you know if the beetles are social rather than a group of beetles living together in a high concentration? What are the keys that you'll be looking for?

William - The key thing we'll want to see in the end, and this will unfortunately mean killing them, is the extent to which the females in particular are reproductive. If we got a hundred beetle sin one log, we'd collect them all and see if there is a queen beetle who is full of eggs, and lots of worker beetles who aren't. So we're looking for the extent to which reproduction is concentrated in one individual rather than being spread evenly across the whole colony. No-one knows that at all for this group at the moment.

- Insect Conservation

The Naked Scientists spoke to Matt Shardlow, Conservation Director of Buglife

Insect Conservation
with Matt Shardlow, Conservation Director of Buglife

Chris - Tell us a little bit about your work.

Matt - We're a little charity called Buglife and we were set up four years ago to fill in the gap in the conservation agenda where there hadn't been an organisation promoting the conservation of all British invertebrates, of which there are 44000. They're incredibly important little animals that do all sorts of jobs like pollinating flowers, keeping wildlife alive, and are the little cogs that keep the world going round. Without them all the other wildlife would be in trouble. We were set up as a new charity to try and deal with some of the conservation issues specific to invertebrates.

Chris - You've very kindly offered to give a year's membership to the winner of our competition this evening. What will that entitle them to?

Matt - As a member they are part of Buglife and supporting the work that we're doing and making sure that there are some more invertebrates out there. You'll also get some of our updates and posters and access to our website, and so on.

Chris - Now one of the things you're looking at are brown field sites; in other words sites that people have built on and become derelict. They're important for these kinds of animals allegedly.

Matt - Absolutely. Brownfield sites are actually as important for endangered invertebrates as ancient woodlands. So we think of some of these natural sites as being very natural and very untouched by human hands and being very important for wildlife. Actually, some of the sites that we've been mucking around with are also very important to wildlife. For instance, old sand quarries such as near the Thames Gateway where these sites are close to the sea, you find invertebrates living in these old quarries that would have been found in the salt marshes. Of course the salt marshes are now all covered in sea defences so there's nowhere left for these animals to live. However, these brown field sites have a lot of other features that are important to wildlife and important to invertebrates.

Chris - It's quite ironic that we've created an area of human habitation and therefore a niche for these animals, and we might end up having to conserve areas of the countryside that we've initially damaged in order to save these species.

Matt - Yes. We tend to think of green fields as being analogous with wildlife rich and wonderful Eden-like things. But if you actually look into what falls into the formal classification of a green field, it also includes brown arable fields that are sprayed repeatedly with pesticides. Most of the pastures out there have very few wild flowers left in them. They're covered in fertilisers, which is bad for the invertebrates, and they're sprayed in pesticides which is bad for the plants and the invertebrates. So in terms of a rich ecosystem, these ecosystems are relatively rare. A lot of these places where there are lots of wild flowers and lots of nectar and pollen sources, there's also lots of bare ground and things to nest in and bask in which lots of these invertebrates love to do.

Chris - What sort of animals are we talking about here Matt?

Matt - Wasps, beetles, bees, butterflies and things like the Dingy Skipper for instance. Also bumblebees. Bumblebees need these large areas to go and forage and get all their nectar from so they can get the next generation of queens out for the next year. Without these areas of brown field, there would be much smaller nectar resources for a lot of these bees and they'd be going extinct. They're already declining rapidly. Many bees are only hanging on in the Thames Gateway on these large brown field sites that still have wild flowers on them.

Helen - They all sound fantastic all these bugs that we can find. What do people who live nearby think of these insects? Are they aware of them or are they hidden away so we don't really see them?

Matt - They're becoming more aware of them and that's on eof the reasons that Buglife was set up. Bugs get a lot of bad PR and mosquitoes being out to get you and new invasives being out to destroy the countryside. But no-one's out there saying, look, these bees pollinate our crops. Two out of every three mouthfuls of food we eat is there because of pollination and 80% of the crops that are grown in Europe are pollinated by invertebrates. If we're looking at an environment that's sustainable, we need to protect pollinators. Who knows what we're going to be growing in a hundred or two hundred years time? We need to be able to feed our children and grandchildren.

- Can urine neutralise a jellyfish sting?

There's a myth (or is it truth) that urine from a human can negate a jellyfish sting. Is that an urban legend?

Can urine neutralise a jellyfish sting?

I've been looking in to this but there doesn't seem to be a very clear answer as to whether or not urine does help with jellyfish stings. The idea is to try and reduce the pain, but also, if you have a tentacle stuck to you, to try and prevent any more of those nematocysts from firing. I was looking round and I couldn't find any scientific studies that were prepared to look at why urine might have an effect on this. It certainly is something of a traditional treatment and it's something you have access to if you don't have access to vinegar. Vinegar is a much more usual treatment for jellyfish stings and has been tested. There was a study reported in New Scientist a few years ago saying that they tested coca cola and four day old wine because they're very acidic. They can help reduce the pain and stop the firing of these nematocysts. We think it might be something to do with the vinegar dehydrating the nematocyst cells and stopping them being able to fire. But if you only have urine, it might work. Also, males have more sterile urine than females, so if you can ask a male to provide the necessary, then that's great.

- How many flies do humans accidentally eat?

On average, how many flies do we accidentally eat every single day?

How many flies do humans accidentally eat?

I'm not quite sure but commercial companies have actually quantified the amount of insect material we're allowed to eat and drink in chocolate and cornflakes and so on. If they're quantifying it, then we must be eating it. In chocolate you measure insect parts per million. I would say we probably eat more than we would like. A little extra protein perhaps. People catch flies in great numbers in Lake Victoria, they're called Lake fly, and I have eaten them. They taste like shrimps, which is rather unexpected! They look like tiny midges and come in huge clouds. They compact them down into small fly cake. Flies are delicious! They were just dried and it's a good way to do something with the huge biomass emerging from the lakes. I've had fried termites in Uganda and they're nice too.

- Are insect compound eyes blinded by the sun?

Why are insects, which have composite eyes, not blinded by the sun? Apparently they have no eyelids that they can shut, and my friend Wen...

Are insect compound eyes blinded by the sun?

I think they probably were quite irritated. Insects can be temporarily blinded by very bright light, but when they go into the dark again, their photo-pigment would be regenerated. There are some ants that live in very bright conditions in the desert. They would have pigment that would protect their sensitive photocells. In addition to that, all their neural machinery behind their eyes would act to adapt to avoid bright lights. The whole system is geared up to adjust the gain, like if you point a video camera at a bright scene. You can see that the camera adapts. That's what an insect would do if it lived in a very bright condition.

- What is causing bees to die off?

It's well known in the USA that bees are dying. This is having profound effects on certain types of agriculture. Why are these bees dying...

What is causing bees to die off?

There is a varroa mite which is rushing through populations of honey bees in Europe, but I'm afraid I don't know about the American situation. This is a very serious pest, which is causing a lot of concern in European hives. I imagine the same thing is happening in America but I'm afraid I don't know. The mite gets into the cells where the larvae are growing and eats and kills them. It's very contagious and gets from colony to colony while doing large amounts of damage. Bees are very hygienic and spend a lot of time cleaning. I imagine this is a relatively new thing that has come into their system and they're not yet properly adapted to it.

- What were these beetles with eyelashes?

I found a couple of beetles over an inch long and the shell looked like a withered acorn. The wing span was nearly two inches. The antenn...

What were these beetles with eyelashes?

A beetle with eyelashes on the end is like a scarab beetle or a chafer beetle. The technical name is Lamellicorn beetles. They use the antennae for picking up pheromones, scents and chemicals and things. So it could be some kind of chafer beetle, a rosechafer or something like that. It's also a good idea to look for a picture on the internet, as you'll find out for certain what it is you have found.

- Do ants sleep?

I saw a bunch of ants that were crowding around some food crumbs on the pavement. Do ants sleep? They seem to be running around all the t...

Do ants sleep?

Someone's looked at ant behaviour patterns by following the whole colony over a matter of days, and they have very definite patterns where the whole colony seems to shut down and rest. They then start again in a few hours until in a very specific rhythm, they stop again. They do have rhythms of behaviour although I'm not sure whether that's sleeping, but at least resting. They're not active all the time.

- How do cockroaches get through impossibly small gaps?

I work in a bakery and years ago we used to get a lot of cockroaches. We used to stack the bread tins inside one another. There was hardl...

How do cockroaches get through impossibly small gaps?

Although cockroaches are quite big insects, they're quite flat dorso-ventrally, so that they might have been able to crawl in through a very small hole. Alternatively, if they had laid their eggs between the tins, the eggs may have hatched and perhaps developed there. They're very flat and could squeeze in.

- How did ants find my honey jar?

My mother left the lid off a jar of honey in a food cupboard. We'd never seen any ants there before, but they'd managed to form a line to...

How did ants find my honey jar?

It's not radar. They just have scouts that are foraging round from the home colony, and when one does hit a nice bit of food like your mother's food, he or she will then go back to the colony and recruit lots more. They then form a trail to the honey. There are also many species of ant. There are several thousand in the world and they're probably one of the most important species in the world.


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