Cockroaches

Question: What can I do about the large cockroaches invading my house?

Answer: Cockroaches are problems to homeowners, and they may transfer diseases or cause allergic reaction. Some cockroaches live their entire lives inside homes or buildings. These are referred to as domestic cockroaches and the primary example is German cockroaches. The larger cockroaches like you are seeing live both inside and outside. The main species are the American cockroach, oriental cockroaches, and the smokybrown cockroach. They often move indoors when the weather outside becomes too cold, too hot, too wet, or too dry. Though they normally do not survive well inside, the American and oriental cockroaches can make a good living and successfully breed indoors if they can find an area with enough moisture and food.

Here are some tips for inspecting and managing these pest from Dr. Xing Ping Hu, Extension Entomolgy Specialist from Auburn University.

The best time to inspect is just after sunset when roaches become active. Inspection should start with checking the building exterior. Roaches may hide in cracks and crevices on outside walls and foundations, under siding and weep holes/openings around pipes, wire, and cables where they enter buildings.

Check landscaping and building surroundings: Since roaches like moist and shady areas, inspect around garbage cans and dumpster area. Check areas under trees and shrubs that have lots of leaf litter or mulch. Also, check rotting stumps or logs on the ground, wood piles and tree holes, compost or debris piles, planters and pots near the foundation of the building. Sewers are another place you should not miss, especially for the American cockroach that often lives and breeds in sewers and can invade buildings directly from the sewer system.

Check above, too. These cockroaches also can be found under roof overhangs and in roof gutters where they live and feed on collected leaves and debris.

The key to successful management involves an integrated approach of prevention, exclusion and pesticide usage. The following six-step program will greatly reduce your problem with these larger cockroach species.

One, when cockroaches are found on the exterior, treat the cracks and crevices where they are hiding with a residual insecticide. Use liquid insecticides or granular insecticides in infested sites around the foundation, especially around windows, doors and other entry points. Treat infested cracks and crevices with a liquid residual or dust based insecticide.


Two, make sure cracks and crevices are then caulked or sealed. Seal openings around windows, doors, vents, pipes and electrical conduits.

Three, install door sweeps, thresholds and weather seals on doors.


Four, reduce outside lighting and/or use yellow instead of white bulbs.

Five, move stacks of firewood, lumber, stones, etc., away from the homes foundation. Clean gutters and avoid heavy mulching around the foundation. Also, dead tree stumps and debris piles that can’t be moved should be treated with a granular bait insecticide.

Finally, apply a regular perimeter barrier insecticide treatment to keep these cockroaches from moving into the home.