Cockroaches can measure over 50 mm (2 in) length, with tropical species tending to be larger than those found in other climates. Cockroaches have six legs, two antennae and some have wings. However, most winged cockroaches are not particularly adept at flying.
Cockroaches belong to Kingdom Animalia, Phylum Arthropoda, Class Insecta and Order Blattaria. Some species invade human dwellings and are considered pests. Others are beneficial to the environment as important recyclers of decaying organic material. The pest cockroaches can be carriers of various diseases because they are commonly found near waste deposits or in the kitchen, where food is present. Restaurants may also experience cockroach infestations.
Cockroaches emit unpleasant odors and may also produce sound. The Madagascar hissing cockroach is the most famous of these vocal cockroaches, although more common species may produce quieter clicking or chirping noises.