250 million years ago, cockroaches existed, which were similar to those we know today. They are considered to be primitive insects. The vast majority of cockroach species live out in the open and do not come into contact with humans. Usually cockroaches are primarily tropical insects. The cockroaches which now live with us in houses probably came here a few hundred years ago.
Cockroaches are rather large insects with biting mouth parts and long, very movable legs. When they have wings, the forewings are large and leathery, while the rear wings are folded, fan-shaped wings underneath them. The development takes place through a number of juvenile stages, the so-called nymphal phases that resemble the adults, but are smaller. The eggs are laid in an egg capsule that holds several eggs. Normally, not much damage is actually caused by cockroaches. However, there will always be the risk of the transfer of bacteria to food.