Gromphadorhina portentosa Madagascar Hissing Cockroach

The easygoing nature of the Madagascar Hissing Cockroach makes them a good starter pet for owners who are new to insect keeping. These shiny brown, oval-shaped cockroaches grow to approximately 2 to 4 inches long and weigh 1/4 to 7/8 ounces. 

Though they can’t fly, they can scale smooth, vertical surfaces using special, sticky pads and tiny hooks on their feet. In the wild, it has no trouble scaling branches and tree trunks, navigating thick underbrush and climbing slick rocks. These cockroaches live on forest floors, where they hide amidst leaf litter, logs, and other detritus. At night, they become more active and scavenge for meals, feeding primarily on fruit or plant materials.

Hissing cockroaches have a pair of modified spiracles; these are the tubes insects use for breathing. These insects use these spiracles to produce the hissing sound that inspired their name. They produce special hisses for aggressive encounters, mating rituals and emergency situations. Each Madagascar Hissing Cockroach has its own characteristic sound, and the cockroaches can distinguish between each other’s hisses. 

Males have large horns, which gives them an unusual and impressive appearance, and  use them to ram one another’s heads and flip one another over. They can also flick their abdomens to forcefully whack another male often resulting the hissing sounds that these roaches are known for. A male might claim a specific rock or a fallen log for months at a time, rarely leaving its territory. These roaches hiss loudly to enforce the hierarchy of the colony and to ward off intruders. Males also hiss when trying to attract a female and during mating. Males use a long-range hiss to call to females and a short-range hiss to talk to roaches that are nearby.

Females appear to bear living young, but nymphs actually emerge from an egg case called ootheca. In most cockroach species the female drop the ootheca on the ground or deposit and glue it to something. In the Madagascar Hissing Cockroach, the ootheca is retained within the body of the female until eggs hatch. A female can produce up to 750 young in her lifetime.


The nymphs molt six times during the course of their lives. At the last molt they become sexually mature adults. After a  molt, cockroach nymphs sometimes appear white or very pale. They’re particularly vulnerable during this time because their new exoskeletons aren’t ready to protect them. The nymphs regain their color as the keratin (the protein that also forms hair, feathers and claws on other animals) that makes up their exoskeletons hardens. Sometimes, cockroaches eat their old exoskeletons to recycle the nutrients contained in them.


Tiny mites, Gromphadorholaelaps schaeferi, living on the surface of Madagascar Hissing Cockroaches help decrease the  presence of a variety of molds on the cockroaches’ bodies, potentially reducing allergic responses among humans who handle the popular insects. The mites eat saliva and organic debris that collects along crevices of the lower middle portions of their bodies & between the cockroaches’ legs. The mites also obtain moisture from the spiracles through which the cockroaches breathe.The mites cannot live anywhere else but on the surface of the Madagascar hissing cockroach and pose no threat to humans and other pets. About 20 to 25 mites live on each adult cockroach. The adverage lifespan of the cockroaches is extended by approximately 9 months when infested with these mites. There is no odor associated with these cockroaches or their feces.

Madagascar Hissing Roaches