Can a cockroach live without its head?

Lose your head and you lose three things at once: you stop breathing, you bleed out, and your brain stops telling your body what to do. A cockroach loses none of those. It breathes through spiracles, small openings along its sides, which do not take orders from the brain. Its circulatory system runs at low pressure, so the wound simply clots shut.

Control is spread out too. Each segment of the body has its own knot of nerve tissue, so a headless cockroach can still stand, respond to touch and walk away from you, which is the kind of thing that does not get less unsettling with explanation.

What finally ends it is the missing mouth. Cockroaches can go a long time on a single meal, so hunger is not urgent, but they cannot drink, and after a week or two they dry out. Entomologist Christopher Tipping, speaking to Scientific American, kept some alive in a jar for several weeks. The heads, for what it is worth, also survived for a few hours and waved their antennae.