Appearance
Most species of cockroach are about the size of a thumbnail, but several species are larger.
Cockroaches have a relatively small head and a broad, flattened body, and most species are reddish-brown to dark brown. They have large compound eyes, two ocelli, and long, flexible antennae. The mouthparts are on the underside of the head and include generalized chewing mandibles, salivary glands and various touch and taste receptors.
The body is divided into a thorax of three segments and a ten-segmented abdomen. The external surface has a tough exoskeleton which contains calcium carbonate; this protects the inner organs and provides attachment to muscles. This external exoskeleton is coated with wax to repel water. The wings are attached to the second and third thoracic segments. The tegmina, or first pair of wings, are tough and protective; these lay as a shield on top of the membranous hind wings, which are used in flight. All four wings have branching longitudinal veins, as well as multiple cross-veins.
The three pairs of legs are sturdy, with large coxae and five claws each. They are attached to each of the three thoracic segments. Of these, the front legs are the shortest and the hind legs the longest, providing the main propulsive power when the insect runs.
Distribution
Cockroaches are abundant throughout the world and live in a wide range of environments, especially in the tropics and subtropics.
Diet
Cockroaches are omnivores, which means they eat both plants and animals. They particularly like starches, sweets, greasy foods, and meats, but roaches are not picky eaters. They'll feast on almost anything that is derived from something that was once a living organism, such as plants and animals.
Behavior
Cockroaches are social insects; a large number of species are either gregarious or inclined to aggregate, and a slightly smaller number exhibit parental care. Cockroaches are mainly nocturnal and run away when exposed to light.
Cockroaches are thermophilic and moisture-loving, they are very mobile insects.
Cockroaches are one of the hardiest insects. Some cockroaches can live up to a month without food, as well as hold their breath for 45 minutes and slow down their heart rate.
Reproduction
Cockroaches use pheromones to attract mates, and the males practice courtship rituals, such as posturing and stridulation. Like many insects, cockroaches mate facing away from each other with their genitalia in contact, and copulation can be prolonged. A few species are known to be parthenogenetic, reproducing without the need for males.
Cockroaches have incomplete metamorphosis, meaning that the nymphs are generally similar to the adults, except for undeveloped wings and genitalia. Development is generally slow, and may take a few months to over a year. The adults are also long-lived; some have survived for as many as four years in the laboratory.
In captivity
Your cockroaches need a terrarium or enclosure which is safe, escape proof and big enough. Young cockroach nymphs can escape through the smallest cracks because their body is really flat. Sliding doors commonly used in terraria have an open space between the doors where young cockroaches can escape through. Some cockroach species can walk onto vertical glass or plastic while others can not. Some species can fly. Be sure to check what your species of choice is capable of to provide it with an escape-proof enclosure.
The size of the tank depends on how many roaches you want to keep and and on their size. Generally speaking the tank should be at least 6 times bigger than the space the cockroaches occupy. In this way there is enough space for them to walk around and to get away from each other if they want to. Bigger is always better.
You need to provide your cockroaches with a good substrate and with hiding places. What is suitable depends on the species of cockroach you keep; some need a moist environment while others need a dry environment. For moist environments you can generally put moist soil at the bottom of the tank. As hiding places you can provide tree bark, flat stones and wood. For dry environments you can cover the floor with oats and you can provide egg cartons or small cardboard structures as hiding places.
Adequate temperature and humidity are crucial to the survival of your cockroaches. Be sure to check what your species needs. A too high humidity will cause death, a too low humidity will cause bad molts, wrinkled wings and also death.
Cockroaches generally eat fruit, vegetables, moistened dry cat food, moistened fish food, rotting wood and rotting leaves. Not all species eat the same. Some species only live of specific food sources such as rotting woods, while others can live off anything.
You can feed your cockroaches just by placing the food in their enclosure. If the food goes bad easily, like fruit and vegetables, remove it before it starts to mold or rot.