The Madagascar hissing cockroach (Gromphadorhina portentosa) is one of the largest species of cockroach, reaching 5 to 7.5 cm at maturity. They are native to the island of Madagascar where they are commonly found in rotting logs. Unlike most cockroaches, they are wingless; The “hissing” sound (expelling air through their bodies) is their primary defense, to frighten potential predators, as they cannot fly and are easily captured. They are excellent climbers and can scale smooth glass. Males can be distinguished from females by their thicker, hairier antennae and the very pronounced "horns" on the pronotum.