Madagascar Hissing Cockroach

Madagascar Hissing Cockroach Gromphadorhina portentosa

Type of Animal:

Forests/woodlands (especially in hollow logs, among leaf litter/rotting wood, & fallen/decaying trees)


Oval-shaped, shiny brown to reddish, wingless, single pair of antennae, males have large horns behind head, females have only small bumps, males have bushier antennae, very large cockroaches, males have 2 large bumps on back

Greens, fruits, vegetables, plant debris, plant material, insects, carrion

Status in Wild:

Not applicable

Large colonies-each male has harem of females, males have hierarchies & are dominant

Additional Info:

Young: Nymph
Group: Colony

Male: 7/8 oz
Female: ¼ oz
2 months 

Life Span:
2 years in wild, 4-5 years in captivity

Body Length:
Male: 4 in
Female: 2 in

Main predators are arachnids, birds, mammals, lizards, & ants.
Play important role as decomposers.
Males use 2 large bumps on back called pronotal horns in fighting. Other times, they’ll compete just w/ hisses.
They’re ovoviviparous, in which females give birth to live young hatching from eggs inside female’s body. Females breed 3-4 times a year & each litter has 30-60 young, meaning that a single female could give birth to 240 young a year & up to 750 in her lifetime.
Sexually mature at 2.5 months old.
Dominant males show off by standing on toes or “stilting.”
Known for at least 5 types of hisses-male combat hiss, 2 courting hisses, a mating hiss, & an alarm hiss (which whole colony does in unison). Hissing done by forcing air through spiracles on abdomen. Males hiss more than females.
Active at night (nocturnal).
They’re great climbers.
Sometimes simply known as a hisser.
Often breed year-round.
Nymphs undergo 6 molts before maturity, adults never molt.

Fun Fact(s):
Raw cockroaches contain mild neurotoxin that numbs mouth & throat.
While often known as household pests, most cockroach species (including these) are not pests.
Bronx Zoo held naming program in 2016 & 2017 for Valentine’s Day, allowing benefactors to name roaches.
Often used in education programs, since they’re odorless, they don’t fly, they don’t bite, & they’re usually very inactive. Same reason they’re sometimes kept as pets.

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