Zombie cockroaches

Cockroaches are infamous for their tenacity, and are often cited as the most likely survivors of a nuclear war. Some even claim that they can live without their heads. It turns out that these armchair exterminators (and their professional brethren) are right. Headless roaches are capable of living for weeks.

They are zombies. So is a headless cockroach kind of like a robot (or a biot) in that it's purely a biological living thing with no thought? Or does a cockroach brain do any thinking anyway? Probably not.