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Animal Fact Sheets

Hissing cockroach range map


(Gromphadorhina portentosa)

Classification and Range

Cockroaches belong in the class of arthropods Insecta, and are classified into the order Blattaria. Five families of cockroaches are in this order: Cryptocercidae, Blattidae, Polyphagidae, Blattellidae and Blaberidae. The Madagascar hissing cockroach is in the family Blattidae. Cockroaches are found on every continent, including Antarctica. However, as its name suggests, the Madagascar hissing cockroach is found only on the island of Madagascar.


Forages on the floor of tropical forests, near river banks and around logs or trees; nocturnally active.

Physical Characteristics

The body can be up to 2.5 inches (6.35 cm) long, no wings are present. Weight varies, from .2 to.3 ounces (6-8 gr)

Life Span

One year or longer. Life span in the wild unknown; up to 2 years in captivity.


In the wild: Various plant and animal matter
At the zoo: Monkey chow, various fruits and vegetables.


Mating can occur year-round, and is contingent on warm temperatures. When a female is ready to mate, she may give off a special scent to attract males. The male circles the female, hissing and touching her antennae. If the female is receptive, she crawls over the male's abdomen, while dragging her abdomen over his. Then, the male thrusts the tip of his abdomen towards the tip of her abdomen. The female may also stand on the ground, while the male copulates with her. Mating takes place, as the pair position themselves rear to rear. After separating, the female stores fertilized eggs in her ootheca, a 1 inch (2.5 cm) long, yellowish egg case. The ootheca may be kept inside or outside the body of the female.

A few months later, 15 to 40 cockroach babies, called nymphs, are born. Nymphs are 1/4-1/2 inch (6.4-12.8 mm) in length, and flat, like a small watermelon seed. Nymphs stay with their mother for quite some time after hatching. Nymphs mature in about five to 10 months, and once they reach juvenile stage, they set out on their own.

Life Cycle

All cockroaches have enemies, such as other insects, mammals, reptiles, amphibians or birds. Cockroaches must also contend with an even smaller species of insect, the cockroach mite (a parasite), which feeds on the cockroach's body.

Once full-grown, hissing cockroaches exhibit sexual dimorphism, which means that the males and females act or look differently. Male hissing cockroaches have a set of protrusions, resembling two humps, on the front of their body. They use these "horns" to ram other males when establishing or defending their territory.

Habitual Hissers

The Madagascar hissing cockroach has a unique defense mechanism. Along each side of its body is a row of holes, called spiracles. These spiracles are used for respiration. When the Madagascar hissing cockroach is threatened, it depresses its abdomen, ejecting air out of its spiracles. This produces a loud hissing noise which can startle a predator, giving the cockroach a chance to escape. Additionally, hissing is used as a means of communication during courtship and mating, or by males to defend their territories from other males.

Crafty Cockroaches

Cockroaches are considered one of the most primitive of insects, having changed little in the last 250 million years. Without a doubt, cockroaches are one of the world's most rugged animals. For example, some species of cockroaches are immune to levels of radioactivity, that would be lethal to humans. Certain cockroaches can also survive up to a week after losing their head; they die only from dehydration, for they have no mouth with which to drink water!

All insects have three body segments: head, thorax and abdomen. Yet, from a top view, the Madagascar hissing cockroach does not look like the typical insect. It appears to have only one continuous body segment connected by its outer shell. This outer shell extends to protect the head and the entire body of the Madagascar hissing cockroach.

Location at the Zoo

Remarkable Madagasgar hissing cockroaches are currently not on view at Woodland Park Zoo's Bug World. However, you''ll go "buggy" while viewing exciting seasonal displays that take you on a journey to different bioclimatic zones around the world. You may come face-to-face with recycling cockroaches, assassin bugs, web-spinning spiders or scuba diving beetles, to name only a few. The only way you'll find out which bugs you'll encounter is by visiting Bug World. Don't miss it!

Conservation Connection

For humans, cockroaches pose little threat; practically all species of cockroaches are beneficial to their environment, and they are an invaluable aid in recycling a large majority of the Earth's dead or decaying plant and animal matter. For example, tropical forests have been called "green deserts," because their soils are poor in nutrients. The forest vegetation appears to be lush, but it has survived only through ingenious life-support systems. Cockroaches are one of the building blocks of these systems. Without cockroaches, dead and decaying vegetation would smother tropical forests.

Many people associate cockroaches with the spread of disease. Unlike mosquitoes or fleas, cockroaches do not spread disease via direct transmission (i.e. through the blood as the result of a bite). Instead, cockroaches inhabit unsanitary areas of food storage, bringing with them microbacterial agents of decay. In turn, these agents contaminate our food supplies with pathogenic organisms. It is these "hitchhikers" that spread disease, not the cockroaches. To prevent cockroaches from becoming pests in your home, clean your kitchen often, store your foodstuffs properly, and quickly dispose of spoiled food.

How You Can Help!

The effort to save animals and their habitat requires cooperation and support at the international, national, regional and individual levels. You can help in this cause. Join and become active in Woodland Park Zoo and other conservation organizations of your choice. To conserve habitat for giant water bugs and other insects, reduce your use of pesticides and herbicides, and work to preserve vegetation in your neighborhood and in tropical regions.

Contact Woodland Park Zoo at to find out how you can support conservation efforts at the zoo. Learn other ways you can help conserve wildlife and the habitats they require for survival by visiting our How You Can Help page.


Hissing Cockroach Fascinating Facts

  • Females can produce up to 30 ootheca in one lifetime, resulting in over 750 young!
  • The largest cockroaches in the world, Megaloblatta lonipennis, have wingspans up to 7 inches (18 cm) in width!
  • There are over 3,500 species of cockroaches, but fewer than 30 species are considered pests to humans!

Sources and Suggested Reading

Cornwell, P. B. 1968. The Cockroach (Vol. 1): A Laboratory Insect and an Industrial Pest. Hutchinson & Co., London.

Roth, L. M. and Willis, E. R. 1957.  The Medical and Veterinary Importance of Cockroaches. Smithsonian Institute, Washington DC.

For Kids!

Gordon, D. G. 1996. The Compleat Cockroach. Ten Speed Press, Berkeley, CA. 178 p.

Zoobooks. 1994. Insects. Wildlife Education Ltd., San Diego, CA. 18 p.

Zoobooks. 1994. Insects 2. Wildlife Education Ltd., San Diego, CA. 22 p.