Fossil evidence indicates that cockroaches have inhabited the Earth for approximately 300 million years, remaining relatively unchanged through the ages. Most cockroaches are indigenous to tropical climates, but have been dispersed the world over through various means. The so-called American cockroach, for example, is believed to have come to the U.S. from Africa aboard slave ships, while the Oriental cockroach seems to have hitched a ride from the Southern Pacific to the States via returning WWII soldiers. Because of the tropical origin of the insect, cockroach problems tend to be most severe in warmer climates, though colder regions are certainly not immune to infestation.

Although cockroaches have wings and are closely related to grasshoppers, most of them either don't fly at all or can't stay aloft for more than a short, fluttering leap. They feed on all types of decaying organic matter and prefer to dine at night. Their less than selective eating habits make them poor companions for humans: Food is never safe from contamination when cockroaches are around, and a heavily infested home is likely to become foul smelling and germ ridden if left untreated.

More than fifty species of cockroach currently call North America home; but of that number, just four are likely to take up residence in your home (the others prefer a woodsy, outdoor existence and so cause few problems for humans).