The cockroaches are an ancient group, dating back at least as far as the Carboniferous period, some 320 million years ago.

Currently, 4,600 species and over 460 genera are described worldwide, but just 30 are considered pests. Of those 30, four are especially adept at making a nuisance of themselves: the German, American, Australian and Oriental cockroaches. Unfortunately, all four of those species occur in the U.S.

The German cockroach reproduces faster than any other residential cockroach, growing from egg to reproductive adult in roughly 50 to 60 days. One female and her offspring can infest a home with more than 30,000 cockroaches in just a single year.

Unlike most insects, which lay eggs, the Giant burrowing cockroach gives birth to her young, and protects her offspring in her underground alcove, providing them with leaf litter she gathers over night. They can live for up to 10 years and parenting cycles can last up to six months, until the young (called nymphs) are capable of leaving the nest.

The Cuban cockroach or green banana cockroach is sometimes kept as a pet due to its relatively pleasant lime green color and because it is not an invasive indoor species. It is also used as food for other pets.

Cockroaches don't have ears, but they do have tiny hairs on their legs that they use to pick up sounds.

Megaloblatta longipennis, found in Peru, Ecuador and Panama, can grow to 9.7 centimetres (3.8 in) in length and have a wingspan of up to 20 centimetres (7.9 in).

Cockroaches are omnivorous scavengers and will consume any organic food source available to them from plant matter to people food, dead skin cells, hair, garbage and even feces.

Due to their open circulatory system, and the fact that they breathe through little holes in each of their body segments, they are not dependent on the mouth or head to breathe. However, without a mouth, they cannot drink water and will die from dehydration in about a week.

In 1991 two scientists at the University of California, Berkeley, used a pressure-sensitive plate and high-speed cameras to track eight American cockroaches (Periplaneta americana). In the tests they covered 1.5 metres (5 feet) in one second, achieving a speed of 5.5km/h (3.4mph).