The scientific name of a cockroach is Blattaria. There are around 4,600 species of cockroaches in the world and only 30 of those live in human habitats.
All species of cockroaches are omnivorous, meaning they eat a variety of foods. They prefer meat, starches and sugary items, and often eat decaying matter. Most species are nocturnal although the Oriental roach is attracted to light.
Cockroaches are a unique species in that they leave pheromones in their feces. They do this so that other roaches will quickly and easily find food and water and this type of behavior is often seen by humans as swarming. Roaches also prefer to live in groups, unlike many insects.
Most cockroaches are small, only around an inch in length. However, some species grow much larger. The Central American giant cockroach can grow to be around 3.5 inches long and weigh more than 1 ounce. The longest roach species on record reaches lengths of up to 3.8 inches.
Wild cockroaches have a variety of predators they have to watch out for. Geckos, iguanas, beetles, wasps, toads and frogs all prey on cockroaches but, despite the threats, cockroaches have lived for around 300 million years.
There is a common myth in circulation that roaches cannot be killed with radiation. This is not entirely true. Many types of insects, including the roach, can withstand 10 times the lethal dose of radiation for humans, but it can still kill them.