"Why do most cockroaches die on their backs?
"First, few cockroaches die on their backs in the wild. Natural
death of cockroaches probably occurs in the stomach of a bird, bat
or other small animal.
"Second, Cockroaches are not used to living on a polished marble or
vinyl floor. They are more used to a ruguous living plane including
leaves and sticks and other vegetable debris. Thus when a cockroach
finds itself on its back (by some mistake in its orienteering) it
may have trouble righting itself if there is not debris around to
grab hold of with its legs. (Try it, put a cockroach on its back on
a polished floor with and without some crinkled paper.)
"Third, often we come across dead cockroaches in buildings that
have died of insecticide. Most of these insecticides are
organophosphate nerve poisons. The nerve poison often inhibits
cholinesterase, an enzyme that breaks down acetylcholine (ACh), a
neurotransmitter. With extra ACh in the nervous system, the
cockroach has muscular spasms which often result in the cockroach
flipping on its back. Without muscular coordination the cockroach
cannot right itself and eventually dies in its upside
down-position."
