How freaked out should I be about bed bugs?

Wednesday 28th Feb 2024, 12.30pm

You might have seen them in a hotel. You might have read about them in the news. Maybe you’ve seen them star in social media videos filmed on the London underground. But should we really be worried about bed bugs?

The little critters evolved from feeding on bats and birds to humans thousands of years ago and were part of society for hundreds of years. But with the invention of synthetic pesticides, bed bug populations declined significantly after the Second World War. However, as pesticide resistance grows and the world becomes increasingly connected, bed bugs are making a resurgence.

Entomologist Liam Crowley, from the Department of Biology, tells us what to look out for and how to keep them at bay in our latest podcast. But don’t worry, they’re not as common as you might think!

Read Transcript

Emily Elias: On the list of things that I’m afraid of, I think bed bugs is pretty much up there. I just see them and it just makes my skin crawl. And unfortunately for us, they are a bit of a trend. But is this hysteria warranted?

On this episode of the Oxford Sparks Big Questions podcast, we are asking “how freaked out should I be about bedbugs?”.

Hello, I’m Emily Elias, and this is the show where we seek out the brightest minds at the University of Oxford, and we ask them the big questions. And for this one, we have found a researcher who is ready to help my paranoid brain.

Liam Crowley: I’m Liam Crowley. I’m a postdoctoral researcher in the Department of Biology at the University of Oxford. And I’m currently working on a really big, exciting project called the Darwin Tree of Life Project where we’re trying to sequence the full genome of every single species of animal, plant and fungi in Britain and Ireland. So it’s quite ambitious.

Emily: Okay, well, sadly, we’re not talking to you about that because today you’re going to put my paranoid brain at ease and we’re going to talk about bed bugs, which is obviously an area of expertise for you, I’m sure.

Liam: Yeah, so I’m an entomologist. I study, in particular, insects and I study all sorts of different insects, so things from bees to beetles to bugs. And that does include bed bugs.

Emily: Okay, so these bed bugs, what exactly are they?

Liam: So bed bugs are within a group of insects called the hemiptera. So these are things like shield bugs and plant hoppers and pond skaters. And they’re all characterized by having a rostrum, which is essentially a straw like mouthpart and they use that for feeding. And they’ll put that into whatever they’re feeding, so the herbivorous ones will be sticking it into a plant like an aphid, and they’ll be feeding on the plant sap. And there’s predatory ones like the assassin bugs, which will be sticking it into another insect and feeding on them. And then there are some of them, which are parasites, which are sticking it into the host and feeding on blood, and obviously that includes the bed bugs.

Emily: Okay, so bed bugs are parasites. What exactly is their purpose? What do they do?

Liam: Well, they do what any animal does, they grow, they feed, and they reproduce. In their kind of niche that they naturally evolved in, they are parasites with quite a narrow host range. So bed bugs evolved to feeding on things like bats and birds. And there are some other bugs within the same family which are called the bat bugs, which are still only really feeding on bats. But two species of bed bugs made that switch over to feeding on humans many thousands of years ago and it’s obviously worked out quite well for them because they’re now found all over the planet, in association with people.

Emily: So they don’t have, like, a useful purpose where they’re secretly doing something behind the scenes that are great. They’re just like, straight up nuisance.

 Liam: Yeah. Unfortunately, there are lots of different insects which perhaps people aren’t too happy about or too enthusiastic about, but we can kind of say, well, you know, you might not like these little flies because they’re biting you and they’re annoying, but actually their relatives pollinate chocolate. Unfortunately, with bud bugs, they don’t really have the same kind of saving graces other than the fact, you know, why does any animal exist? It’s just doing its thing and it has its own right to exist in its own way, depending, on your viewpoint.

Emily: Okay, so existential crisis about bugs – we’ll avoid that today and instead get into these crazy videos that I see on the internet where it’s like people are on a bus and all of a sudden, uh oh, zoom in on the seat… there’s creepy crawly bed bugs on the bus seat or on the train. Are these real? Do we know? Are there bed bugs in London?

Liam: Yes. it’s really remarkable story, actually. So bedbugs years ago always used to be quite common and you can find in different historical sources for all around the world, stories about, you know, people being bitten by bedbugs. And that was just kind of a fact of life and people got on with it. Even the saying, you know, night night, sleep tight, don’t let the bedbugs bite. That was literally talking about bed bugs.

But then with the invention of modern synthetic pesticides, so things like, DDT, and then later on pyrethroids, the control really improved and actually the populations declined massively. So following the second world war, really’ through most of the 20th century, bedbugs weren’t that common anymore.

However, what’s happened in recent times is they’ve actually developed resistance to a lot of these pesticides, or we’ve stopped using them, as in the case of DDT, because of the negative impact on the environment. So with this resistance and coupled with the advent of cheap air travel and the much more connected world that we live in, they have undergone, in recent decades, this massive resurgence, and they’re really coming back and forth to the point where actually, yes, they are in the UK. They are definitely in London. And you can find them on public transport.

In fact, a colleague of mine, at the Natural History Museum, was getting the train to work and one happened to crawl across the seat next to her. But as any good entomologist should, she had a vial of ethanol on her and was able to collect that specimen. So at least that won’t be going home as an unwanted guest for any tube passenger.

Emily: Wait, so, okay, the bug was literally crawling next to her. How did she know it was a bedbug?

Liam: Well, yeah, I think actually it was in the seat tray. So she kind of folded down the seat tray and then there it was, just, like, crawling along. And then, she is an entomologist and an expert, and was able to instantly recognize it.

They are fairly distinctive. They’re kind of these small, reddish brownish, quite flat insects. Particularly if they haven’t fed, they’re very flat which helps them in their lifestyle because they hide during the day in tiniest little nooks and crannies and crevices. And then they feed on probably about an average of once a week. But they need to feed on the blood in order to survive and to grow. And then the females, of course, have to feed a little bit more regularly to be able to produce eggs.

Emily: Okay, Liam, none, of what you’re saying is making me feel better. Like, what the heck?

Liam: So I can try and alleviate your concerns a little bit, and say that there’s no evidence that bed bugs are vectors, or transmit any kind of diseases. So, it’s not like mosquitoes, which can transmit all sorts of things, such as malaria. Bed bugs are just a nuisance. It can be a pretty annoying problem because the bites can be quite itchy. But, it’s very, very unlikely to do any serious damage.

Emily: But still, I mean, I don’t want them crawling around my house. How do we get rid of them? You said DDT and all that stuff is out of the window. They’ve got these new resistances. How do you fight them?

Liam: Yeah, the one people who are happy about this recent spread are the pest control industry, because there’s money to be made and so there are methods that can be employed. Using different types of pesticides can work. Obviously you want to be careful with how we apply pesticides because some of these substances are toxic poisons. So you don’t necessarily want to be liberally spraying it around your bedroom.

So, yeah, the main thing is try not to pick them up in the first place. So if you’re going away to hotels and stuff, you can have a little check and see if there’s likely to be bed bugs there. There are some telltale signs. One of them are tiny little spots, reddish brownish spots on the bedding. And this is essentially bedbug poop, which is, because they’re feeding on blood, it’s just kind of partially digested blood. So if you see little spots on that could be an indication that there are bed bugs there.

I mean, I know some people, potentially take a change of clothes on the tube. I’d say that’s probably a bit extreme. Despite the fact that they are in the UK and around the world and their populations are increasing, they’re still not that common. So I know very few entomologists who’ve actually even found one, and I know some who are desperate to find one so they can tick it off their list.

Emily: Do you guys seriously have a list of, like, bugs that you’re trying to find?

Liam: Yeah, yeah, some of us do. Some people take it very seriously as well, even get quite competitive, just trying to see who can find the most. And some of the guys are incredible, they’ve seen, like, tens of thousands of species in the UK.

Emily: Okay, so, like, you guys are busy playing, like, Pokemon go with bugs in real life.

Liam: Yeah.

Emily: And I can get why you would be really excited to find a bed bug, but I would be absolutely terrified and bricking it if I found a bed bug. Is it likely that, like, I should be, I don’t know, freaked out to sit on a seat on the underground then? Like, should I just let this go?

Liam: No, I think you’re okay because you got to think about how many people are going on the tube in London every single day, and then how many people actually end up getting bedbugs. The ones on the tube is kind of more of like a cultural phenomenon. You get these kind of, like you said, TikTok videos and stuff with people getting scary stories. But actually, it’s really mainly just a problem in the hotel industry.

And there’s simple things that most hotels are doing now, like, just, you know, how often they’re giving the rooms a real good clean and temperatures that they wash the bedding, that kind of thing. And then there’s also, in response to this increase, there’s new, interesting ways that we’re researching to try and see if we can control them better. So things like using pheromone lures and little baited traps baited with this pheromone, which you can deploy in a hotel just to monitor to see if there are bed bugs around. And there’s even some really fancy ones which have a little live camera over the bluetooth, or Wi-Fi, and then AI, which is kind of analysing and identifying stuff as it comes into the trap, and if there’s something which it thinks could be a bed bug it then pings an alert to the people monitoring it. So they can put hundreds of these traps across a network of hotels and track down the infestations before they occur.

Emily: Okay, but I don’t need to be doing that in my home. I should just probably, I don’t know, have a good look at myself and make sure I’m not bringing any bugs off the tube into my house. What should I do?

Liam: Yeah. Yeah. I think doing anything at home would be overkill. I don’t know of anyone who’s had them in their house. I mean, some people do, but it’s normally when they’ve, like, picked up second-hand furniture or something and they’ve been maybe one or two tucked away in a crevice in it.

Emily: Okay, stop taking couches off the street and I should be fine.

Liam: Yes.

Emily: This podcast was brought to you by Oxford Sparks from the University of Oxford, with music by John Lyons and a special thanks to Liam Crowley.

And if you want more insect chat in your life, Liam has a podcast. It is called Endocast. It is on indefinite hiatus, but there is an archive ready for you to dive into about everything entomology.

Tell us what you think about this podcast, The Big Questions. We are on the internet @OxfordSparks. You can also find our website I mean, how many times I’ve said that? You should know that by now.

I’m Emily Elias. Bye for now.