A Cockroach Can Live for a Week Without Its Head

Cockroaches have a decentralized nervous system with ganglia (clusters of nerve cells) distributed throughout their body, meaning their brain isn't solely responsible for all functions. They breathe through small holes in their body segments called spiracles, not their head. Their open circulatory system means blood pressure doesn't drop catastrophically if the head is removed. Eventually, a headless cockroach dies from dehydration or starvation, not from the immediate trauma of decapitation.