A North Carolina State University team tested the theory by giving cockroaches a choice of jam or peanut butter. They then analyzed the insects' taste receptors, similar to our taste buds. Cockroaches recommend good food sources to each other by communicating in chemicals. The scientists found that mutant cockroaches had a reorganized sense of taste, making them perceive the glucose used to coat poisoned bait not as sweet but rather as bitter.
There are about 4,600 species of cockroach and fewer than 30 of these are considered pests. (There are about 5,400 species of mammals).
The world's smallest cockroach is only 0.3mm long and lives in ant nests.
The heaviest cockroach is the huge Australian Rhinoceros Cockroach at 8cm in length.
Dung beetles are similar in looks. When I lived on the Gold Coast in Queensland, Australia, I saw the clever little dung beetles rolling away every dog dropping within a day to leave the park fresh and clean. Insects can work for us as well as against.
Apparently, one of the primary causes of the fear for cockroaches is a more generalized fear of insects. Insects are an integral and influential part of our culture as illustrated by their infiltration of our language, arts, history, philosophy, and religion. However, as human society has become more urbanized, insects have become more estranged. Most people are at least wary, if not fearful, of certain insects. This may be a reasonable fear based on knowledge or experience (bees, wasps, spiders, mosquitoes), or an unreasonable but culturally understandable repulsion (cockroaches or flies).
Cockroaches also have sensors on their bottoms to detect the direction of airflow, so they can get away from impending attacks. So vacuum cleaners cause them trouble. If you put a vacuum cleaner nozzle behind a cockroach, the wind goes from the cockroach's head to the nozzle, so it thinks something's approaching from the front and runs away—straight into the vacuum cleaner.
Clever and adaptable creatures, cockroaches have been on the earth for more than 400 million years. It doesn't look as if scientists have worked out how to trick them yet.
If you step on people in this life, you're going to come back as a cockroach—WILLIE DAVIS