Science Focus - the home of BBC Science Focus Magazine
Can a cockroach really live without its head? © iStock

Can a cockroach really live without its head?

Subscribe to BBC Science Focus Magazine and get 6 issues for just £9.99

"Off with their heads!" might not be much of a threat for these seemingly-immortal insects.

Asked by: Amir Montazer, Iran


Decapitation is almost immediately fatal to humans because we have a high-pressure circulatory system that we depend on to keep our tissues oxygenated. Cutting the carotid arteries in your neck would cause you to bleed out completely in a few minutes. Even if the cuts were immediately cauterised, your body can’t survive without nerve signals from the brain telling you to breathe.

But cockroaches, like most insects, are different. They breathe passively through a network of pipes connected to holes called spiracles along the length of their body. They don’t rely on blood circulation to move oxygen around and their body fluids are at a much lower pressure anyway. Their brain mostly handles the sensory input from the eyes and antennae, with many other behaviours, like running and reacting to touch, handled by ‘mini brains’ called ganglia in each body segment. A decapitated cockroach will eventually starve to death but this can still take several weeks.


Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.


luis villazon
Luis VillazonQ&A expert

Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.


Sponsored content