Submitted: Apr 23, 2008 - Entomologists estimate there are between 5 and 10 million species of insects on Earth. But if asked which insect they hate the most, many people would choose just one -- the cockroach.

Whether they're digesting wood pulp in a rainforest or hiding under a refrigerator, cockroaches are fascinating. They're primitive insects -- they existed millions of years before dinosaurs did and have evolved…