Madagascar hissing cockroach

Gromphadorrhina portentosa

Madagascar hissing cockroaches live in forests on the island of Madagascar. They are herbivores. They live in hollow logs and scavenge amid the leaf litter and rotting wood of the forest floor for food like fallen fruit.

Did you know?

  • 99 percent of all cockroach species are not household pests.

Cockroach lingo

  • Many insects lay eggs, but female Madagascar hissing cockroaches create a cocoon-like egg case called an ootheca and carry the eggs (and neonatal nymphs) inside their bodies. They then bear up to 60 living young, called nymphs.
  • Cerci are two appendages (body parts that extend from the main body) that the roach uses to sense objects in its environment. The two cerci are at the end of the abdomen.

Hissing cockroach behavior and facts

  • Hissing cockroaches live in large colonies.
  • They hiss when threatened by a predator, to sound an alarm for other roaches in their colony or during male cockroach fights. Small holes called spiracles on their backs are used for breathing. If they force air out of the spiracle quickly, it makes the hissing sound. This audible use of the respiratory system is more common in vertebrates (as when humans emit a heavy, noisy sigh). Most insects that make noise do so by rubbing body parts together or by vibrating membranes.
  • They're most active at night.
  • Males sport large horns, which they use in aggressive encounters like the battles between horned or antlered mammals. Rivals ram each other with their horns or abdomens and hiss as they fight. Winners hiss more than losers, so the sounds may help determine a roach hierarchy.
  • They're an important link in the food chain, breaking down forest debris and providing food for larger animals.

From birth to death

  • Lifespan: up to 18 months
  • Vital statistics
  • Length: 2 to 3.5 inches


Not listed

Madagascar hissing cockroaches, the Oregon Zoo and you

The zoo's hissing cockroaches live in the Insect Zoo. They are fed a diet of fruit.