Spray one of these filthy creatures with insecticide, and some time later the roach will be dead, back down, legs facing the heavens. Did you ever wonder why cockroaches die on their back when we shoot pesticide on them?
Insecticides usually contain chemicals which affect the roach’s nervous system, and causes different enzymes to build up in the cockroach. The extra enzymes gives the insect muscular spasms because of which the it flips onto its back.
If, by some mistake, a normal, healthy cockroach finds itself with its back on the ground, it has a lot of trouble getting back on its feet. If a normal cockroach has difficulty righting itself when turned over, a roach with an affected nervous system would definitely have much more trouble in doing so. The struggle to upright itself finally ends when the poison from the insecticide kills the cockroach.
Of course, not all roaches die lying on their backs – most end up in the stomach of birds or some other animal! Those who had their fate sealed by the pesticide, probably end their life upside down.