If the head of cockroach is removed, it may live for few days because:

1. The cockroach does not have a nervous system.

2. The head holds a small proportion of a nervous system while the rest is situated along the ventral part of its body.

3. The head holds a third of the nervous system while the rest is situated along the dorsal part of its body.

4. The supra-oesophageal ganglia of the cockroach are situated in ventral part of abdomen.