The oriental cockroach, also known as the waterbug or black beetle, is a large species of cockroach, adult males being 18–29 mm (0.71–1.14 in) and adult females being 20–27 mm (0.79–1.06 in). It is dark brown or black in color and has a glossy body. The female has a somewhat different appearance from the male, appearing to be wingless at casual glance, but is brachypterous, having non-functional wings just below her head. She has a wider body than the male. The male has long wings, which cover two-thirds of the abdomen and are brown in color, and has a narrower body. Both sexes are flightless. The female oriental cockroach looks somewhat similar to the Florida woods cockroach, and may be mistaken for it. Originally endemic to the Crimean Peninsula and the region around the Black Sea and Caspian Sea, its distribution is now cosmopolitan.
To thrive, cockroaches need a place to hide. They prefer warm places and a relatively high humidity; they also need a source of food/liquid. The optimum temperature for oriental cockroaches is between 20 and 29 °C (68 and 84 °F). Female oriental cockroaches have vestigial tegmina (reduced fore wings) and males have longer tegmina. Cockroaches are mainly nocturnal. Oriental cockroaches can be elusive in that a casual inspection of an infested dwelling during the day may show no signs of roach activity. Oriental cockroaches can be found in usually damp places such as sewer pipes, sink drains, and any other form of damp areas in households.