The Oriental cockroach is normally an outside species and its activity is usually restricted to ground or belowground level. It favors crawl spaces, areas between the soil and building foundations, underneath sidewalks, landscaping mulches, sewers, storm sewers, garbage cans, and water meters. It lives in warm, damp, shady areas near the ground or other area containing natural debris. Oriental cockroaches will often enter dwellings to find moisture and optimum temperatures (between 68 and 72*F) and are often triggered by drought, drop in temperature, flooded drains, heavy rain, or changes in barometric pressure. When large numbers of roaches occur, overcrowding can lead to the mass migration of roach species.
Oriental cockroaches mainly invade structures under doors and through holes, cracks, and pipes joining crawlspaces, underground ducts, manholes, and sewer line drains. The Oriental cockroach prefers harborage on damp, porous surfaces, such as concrete or brick. Indoors, the most common areas to find an oriental roach include: dark and damp basements, crawl spaces, in sewer pipes, in floor drains, under sinks, or any other damp cool area in the house.