How a cockroach can live without a head

A cockroach can survive for a time without its head: it breathes through openings along its body, and some nervous functions are handled by ganglia in the body segments. This is not immortality: after decapitation, a cockroach usually dies from dehydration and infection, and its inability to eat also prevents long-term survival. Duration depends on species and conditions; laboratory observations range from days to weeks.