Controlling these roaches begins by maintaining outdoor areas. Remove debris from your yard that includes wood piles and other materials. Also be mindful of where you put food, especially dog food, outside and inside. This species is very fond of dark, moist places, and can be found in flower beds or under mulch. In these outdoor environments their diet consists of algae, fungi, leaves and small wood pieces.
American cockroaches enter homes during a change in the weather or a shortage of food and can enter through holes from crawlspaces or underground ducts, steam tunnels, manholes, and sewer line drains. Large numbers of American cockroaches may move into buildings when triggered by blocked drainage systems, heavy rains, or changes in barometric pressure. Once inside, they will still seek out the moistest places and places with food and water. They are commonly found in bathrooms, kitchens, basements, and laundry rooms. Indoor, the American cockroach prefers dark, moist, warm places, often near steam pipes, in boiler rooms, around water heaters, in sewers, floor drains, grease traps, around plumbing, water sumps, and damp basements. In urban environments, their scavenger diet consists of any crumbs or scraps of food including pet food.