Hissing cockroaches are native of Madagascar, an island off the coast of Africa. They are unique among insects because of the hissing sound that they make. Most insects, like crickets, make noise by rubbing parts of their body together.
The hissing cockroaches squeeze air out through special vents called spiracles. These spiracles are part of the roach's breathing system. The roaches make the hissing sound as a form of defense. The males also hiss as part of the courting ritual and during combat with other males.
The female hissing cockroach produces eggs and then keeps them inside a special sac inside her body. The eggs stay inside the female until they hatch. The tiny nymphs emerge alive. Scientists use the word ovoviviparous to describe this process. Depending on the species, a female hissing cockroach can produce as many as 60 nymphs in a single batch.
Male hissing cockroaches have thick antennae and horns that project from the pronotum behind their heads. They use the horns in combat with other males. The horns make the males easy to identify. Neither males nor females have wings, so they cannot fly.
There are several species of hissing cockroaches. The one that is most common with people who raise cockroaches is Gromphadorhina portentosa. It is commonly called the Madagascar hissing cockroach. Adults of this species can reach 3″ in length.
Other species include the dwarf Madagascar hissing cockroach, Elliptorhina chopardi, and the V-horn hissing cockroach, E. laevigata. These cockroaches are similar to the G. portentosa, but they are not as well known.
Scientists think that in their natural habitat, these hissing cockroaches live on the forest floor and eat fruit that has dropped to the ground. They are very popular with people who raise cockroaches. In captivity they usually eat dry pet food, fruits, and vegetables.
Breeders caution that although these roaches cannot fly, they can climb smooth surfaces. They suggest putting a thin layer of petroleum jelly at the top of the container to keep the hissing cockroaches from climbing out and escaping.