April 22nd, 2021 by Sarah Miles

It would seem that there are few creatures that have so many amazing capabilities and attributes as cockroaches. They are commonly thought to be able to survive a nuclear blast, live without their heads, and have pre-historic origins – but are these things true or just urban myths? We take a look at some of the weird and wonderful claims made about these fascinating insects to see whether there’s any truth in them.

Can they survive a nuclear apocalypse?

No, they can’t. While cockroaches are believed to have survived the Hiroshima blast back in 1945 there is no evidence to support this. In reality, the extreme heat would have killed them outright. However, studies have shown that they do have a much higher tolerance to radiation than humans (though, interestingly, scorpions, fruit flies, and wasps can withstand much more), so they may be able to survive severe nuclear fallout.

Can they live without their head?

Yes, but only for a couple of weeks. They have a few things going for them that mean the loss of their head wouldn’t mean their instant demise. The main one is that they breathe via small holes in their body called spiracles, rather than a nose or mouth, plus their breathing is not controlled by the brain. They also have a low-pressure open circulatory system so they won’t bleed to death. And finally, they can survive for several weeks without food. Of course, they would need to eat eventually and without a mouth, they can’t do this so would ultimately starve - but those few weeks are enough to mate, lay eggs, and prolong an infestation.

Are they one of the oldest surviving creatures?

Yes. Cockroaches, as a species, are thought to be around 300 million years old as fossils date them to this period. To put that into perspective, this predates the first dinosaurs by around 50 million years. They are thought to have been in existence before the primordial landmass of Pangaea broke up and created the continents and could account for their presence on every continent of the world apart from Antarctica.

Can they hold their breath for long periods?

Yes, for up to 40 minutes. They do this using their spiracles as they are not only used for breathing but for expelling water vapour as well. When they need to conserve water in their bodies, they will simply close the spiracles and can do this for around 40 minutes. This can also help them survive underwater for a similar period.

Are they faster than a cheetah?

Yes – relatively! Full disclosure: a cockroach is never going to win a race with a cheetah. However, in relative terms - taking into account the number of body lengths they can cover in a second, rather than absolute speed - they are faster. A cheetah can cover 20 body lengths a second, whereas a cockroach can cover 50. This is equivalent in human terms of 200 miles an hour! If you see a cockroach, don't expect it to hang around for very long - you'll need to treat your surfaces with sprays or dusting powder as you won't be able to reliably catch them.

Are they cannibalistic?

Yes. You probably don’t get to survive 300 million years without a willingness to eat pretty much anything. Nothing doesn’t represent a tasty meal to a cockroach, even each other. Cannibalism not only gives them a food source when it’s in short supply, but it also helps them to control the population and reduce the number of mouths they have to feed.

Can cockroaches fly?

Kind of. While some species are quite capable fliers, and all have wings, most use them to glide rather than fly and they can only cover short distances. It’s much more efficient for them to scuttle across the ground, especially given the speed they can achieve.

Can they squeeze into tiny gaps much smaller than their bodies?

Yes, they can squeeze into gaps around a quarter of their body size. This is down to their flexible exoskeleton that they can flatten very effectively. This means they can access pretty much anywhere they want to, and it’s almost impossible to keep them out!