This week I’m going to introduce you to one of our smaller residents, the Madagascar hissing cockroach. Of the more than 4,000 species found worldwide, the hissing cockroach is one of the largest as fully grown adults can reach 7cm long!
Cockroaches can be found all over the world, but only four species are considered to be pests to humans – that is, the American cockroach, the German cockroach, the Asian cockroach and the Oriental cockroach. These are all relatively small with each around the size of a thumbnail, but species found in tropical habitats can grow much bigger with the Australian giant burrowing cockroach growing up to 9cm in length. As household pests, they are also among the hardiest insects in the world and can remain active for over a month without food. They are also resistant to being submerged underwater, can survive outside in our cold winters and are well-known for being up to 15 times more resistant to radiation than humans.
Our hissing cockroaches are found in rotting logs on the island of Madagascar. Unlike most cockroaches, they don’t have wings, but instead are excellent climbers with the ability to climb up sheer glass. Their name comes from the loud hissing noise they make, which can either be because they’ve been disturbed, because they’re trying to attract females or from males fighting with other males. Most insects that make a hissing noise do so by rubbing body parts together, but the hissing cockroach is fairly unique in that it makes its noise by forcing air out of the respiratory openings (called spiracles) found along their abdomen. All insects and most spiders will “breathe” through their spiracles but very few can make noises through them. Males and females look quite different, with males having thicker, hairier antennae as well as protruding “horns” on their heads.
You can meet our cockroaches at our Meet a Creature sessions, held daily at 3pm in the Education Centre in the main zoo square.