Indoor populations tend to forage outdoors during warm weather. Likewise, during the winter months, populations established outdoors will venture inside seeking moisture and warmth.

This is generally an outdoor species, living in wood piles, decaying trees, palm trees and in sewer systems. Cockroaches have flattened bodies that allow them to enter homes through cracks around loose-fitting doors and windows, and where electric lines or pipes pass through walls. They are mainly active at night and hide in cracks and crevices during the day, preferring dark moist sites in attics and basements.

They are also commonly associated with boiler rooms, sewers, steam tunnels, and other warm, moist locations. In residential and commercial buildings, American cockroaches usually infest basements, crawl spaces, bathrooms, and decorative landscaping.

American cockroaches are a "peridomestic species" this means that they generally live outdoors. However, populations can also move indoors and live in human structures. American cockroaches usually live in moist, humid environments but can survive in dry areas if they have access to water. The cockroaches prefer temperatures between 70°F and 85°F and will not survive 15°F. In structures, American cockroaches are common in areas where food is prepared or stored and moisture is plentiful. Indoor populations tend to forage outdoors during warm weather. Likewise, during the winter months, populations established outdoors will venture inside seeking moisture and warmth.

Cockroaches eat almost anything including meats and grease, starchy foods, sweets, baked goods, leather, wallpaper paste, book bindings and sizing. Adults are capable of gliding flights.

American cockroaches feed on a wide variety of materials, including cosmetics, beer, potted plant shoots, wallpaper paste, soap, postage stamps, and fermenting fruit. They can foul human food, clothing, paper goods, and surfaces with their feces and body parts. American cockroaches also produce a strong unpleasant odor. This characteristic odor is not only detectable in infested buildings but is also transferred to items that the cockroaches crawl across when foraging.

When American cockroaches aggregate, their presence is primarily an aesthetic nuisance. However, members of this species are also known to carry infectious bacteria on their bodies and in their gut. These bacteria may be transferred to food and other items that the cockroaches contact. Several bacteria commonly associated with American cockroaches are known to cause food poisoning, dysentery, and diarrhea in humans. American cockroaches also produce allergens on their bodies and in their fecal material. While American cockroaches are not considered to be major culprits of human respiratory problems like some other cockroach species, they have been implicated as a cause of allergic dermatitis and childhood asthma.