At this time of year, we sometimes get calls from homeowners who are finding very large, intimidating cockroaches in their basements or laundry rooms. Earlier in the summer, these occasional pests could be wood cockroaches, but in fall, American cockroaches can show up indoors. These big cockroaches differ from our more common German cockroach in everything from size, to reproduction rate, to the kinds of areas they inhabit.

Size

They’re big! American cockroaches are our largest indoor cockroach. They average about 1-1/2 inches long, with long antennae. They are reddish-brown with a yellowish-brown edge around the thorax behind their head.

Sites

American cockroaches can be found both indoors and outdoors during the summer. In southern states, they can live outdoors year round. In our northern region, they can only survive winters in buildings, or in the warmth of sewers or the heat generated by decomposing materials in compost piles or debris landfills.

American cockroaches are not common in homes unless they have moved into homes from a large population in nearby sewers (See Cockroaches from Sewers) or from landfills. They are more common in commercial buildings like bakeries, restaurants, breweries, grocery stores, or greenhouses. You can even find them in office buildings where they almost always occur only on the lower levels, in basements, storage areas, utility tunnels, or parking garages. American cockroaches like warm, dark, damp areas such as near steam pipes, in boiler rooms, trash rooms, in vending machine rooms, near floor drains, or in crawlspaces.

Habits

Rather than hiding in cracks and crevices like German cockroaches, American cockroaches often rest on walls near the ceiling and can glide from high points. They can also climb vertical surfaces and can run rapidly. They have a strong, unpleasant odor which they can leave on items that they have walked across.

Seasonal Problems

American cockroaches develop slowly with only one generation a year. The population is greatest in late summer and fall when both adult roaches and nymphs are present. In our region, outdoor populations migrate looking for food and warmth and often attempt to move indoors when the weather cools. Fall is when homeowners may have their first encounter with the large American cockroach.

If you’ve seen cockroaches in your home…of any size, color, or persuasion, give Colonial a call. We do pests so you don’t have to!