There are over 4,000 recognized cockroach species worldwide. In scientific terms, all cockroach species belong to the order of Blattaria. Most cockroaches live in warm areas, where they often thrive in tropical and sub-tropical conditions. Each species has its own unique characteristics, and these are important to understand when trying to identify a cockroach species. Given their ability to thrive, and therefore create infestations and health hazards to humans, most species of cockroaches are considered pests.
Some of the more well-known cockroach species include American, German, Asian, Madagascar hissing cockroach, and the smoky brown cockroach. German and Asian cockroach species are found around the world, and are a nuisance in the United States, especially in the south-east and in the Hawaiian islands. The American cockroach is found predominately in the United States and parts of Asia.
The American cockroach is one of the larger cockroach species. They can grow up to 1 1/2 inches (3.81 cm) in length. American cockroaches are easily recognizable by a yellow band that stretches across the head. Though this type of cockroach can be a pest, it is usually found living outdoors.
Asian cockroaches are known for their flying ability. Luckily, they tend to remain outside and make grassy areas their home. Asian cockroaches are slightly smaller than American roaches, and they are solid brown in color.
The infamous German cockroach is very problematic in locations around the globe. This cockroach species prefers to live indoors, and if given the opportunity, it will take residence in kitchens and bathrooms. German cockroaches actually carry their egg capsules with them, which helps protect their young, and up to forty baby cockroaches can be hatched at one time.
Among the largest cockroach species is the Madagascar hissing roach. As its name suggests, this cockroach originates from the island of Madagascar, which is near the continent of Africa. This type of roach can grow up to 3 inches (7.62 cm) in length, and live an average of five years in captivity. While most other roaches are considered a pest, this cockroach is often found as a pet or on display at educational centers. Their hissing is produced through their abdomen, and they are the only insect known to have this ability.
Most cockroach species prefer to live in dark habitats, though the Asian cockroach is an exception to this, and is actually attracted to light. Cockroach diets usually consist of anything available to them, and in scientific terms, cockroaches are omnivores. One species of roaches, known as the wood roach or brown-hooded cockroach, feeds exclusively on rotting wood.
Though cockroaches do not bite and they are not usually aggressive, they can be armful to humans. Cockroaches can carry microbes or germs on the surface of their body and transmit these to other surfaces, where humans can pick them up and become ill. The feces that roaches leave behind can cause asthma, as well as allergies in humans.