If the head of cockroach is removed, it may live for
few days because :
(1) the supra-oesophageal ganglia of the
cockroach are situated in ventral part of
abdomen.
(2) the cockroach does not have nervous system.
(3) the head holds a small proportion of a nervous
system while the rest is situated along the
ventral part of its body.
(4) the head holds a 1/3rd of a nervous system
while the rest is situated along the dorsal
part of its body.