Among the over 4,500 species of cockroach, the most common household species are the American cockroach, the German cockroach, the Asian cockroach and the Oriental cockroach. Cockroaches can measure over 50 cm (2 in) in length and have six legs, two antennae, and sometimes wings.

Female cockroaches carry egg cases on the end of their abdomens; these cases can hold up to 30 or 40 long, thin eggs. The egg capsules can take up to five hours to lay and is bright white in color. The hatchlings are initially bright white and inflate themselves with air over the course of their first few hours, becoming harder and darker within about four hours. Under favorable conditions, the female cockroach can produce 300 to 400 offspring over a lifetime. In some cases, a female may be able to lay eggs for the rest of her life after only being impregnated once.

Cockroaches live in a variety of environments, but generally prefer the warm conditions found within buildings. They are mainly nocturnal and will run away from light exposure. Because of this, you probably cannot see the extent of an infestation. The few that you may see around the home have probably been forced out of hiding due to overcrowding. Cockroaches leave chemical trails in their feces and emit airborne pheromones for swarming and mating. These trails transmit bacteria onto surfaces which other cockroaches will follow to sources of food and water.

Cockroaches are among the most resilient and tough of insects. Some species are able to live up to a month without feeding and are able to feed on some very unconventional food sources, such as the glue from the back of a postage stamp. Others can survive without air for up to 45 minutes.

Because of their nocturnal habits, a cockroach seen during the day is a sign of a possible infestation. They can be found in dark, moist places such as behind refrigerators, sinks and stoves. They may also be hiding beneath mats, behind wallpaper and inside the cracks in your walls. Feces sightings are also a sign of a possible infestation. Small cockroaches’ feces resemble coffee grounds or black pepper. A serious infestation may also result in a strong oily or musty odor.