At a glance
- The American cockroach is the largest common cockroach in the Phoenix area, about 1 1/2 to 2 inches long and reddish brown, with a pale yellowish band behind the head.
- In the Valley, American cockroaches are often called sewer roaches because they breed in sewer lines and storm drains, and they also shelter in water meter boxes and irrigation valve boxes.
- Dry drain traps in rarely used bathrooms, uncapped sewer cleanouts, gaps under exterior doors and openings into the garage are the usual ways American cockroaches get into Phoenix-area homes.
- American cockroach activity rises with summer heat and often jumps after monsoon storms flood Valley sewer lines.
- Platinum Pest Management treats American cockroaches around the foundation, door thresholds, meter boxes and valve boxes, and checks drains and sewer cleanouts where they get in.
On this page
How to identify an American cockroach
The American cockroach is the largest cockroach commonly found in the Phoenix area, and around the Valley it is often called the sewer roach. Adults are about 1 1/2 to 2 inches long and reddish brown, with long antennae and a pale yellowish band around the shield just behind the head. Both males and females have full wings, and in hot weather the adults can fly short distances. Young roaches, called nymphs, look like smaller, wingless versions of the adults.
Where American cockroaches live in the Phoenix area
American cockroaches need warm, damp shelter, and the Valley's sewers and underground utility boxes provide plenty of it. The largest numbers are in sewer lines and storm drains. Around the house, they hide in water meter and irrigation valve boxes, and under landscape rock wherever a drip emitter or leaking valve keeps the ground wet.
Arizona bark scorpions feed on American cockroaches, and where roaches are common around a meter box or foundation, scorpions tend to hunt nearby. Bringing roach numbers down is part of our scorpion control work for that reason.
How American cockroaches get into homes
Most American cockroaches get into a house through the plumbing or through gaps at ground level. These are the entry points we find most often.
- Floor drains and tub or shower drains in bathrooms that rarely get used
- Sewer cleanouts with a missing or damaged cap
- Gaps under exterior doors with worn or missing sweeps
- Openings along the weep screed at the base of the stucco
- Garages, through a worn door seal or gaps around the frame
A P-trap, the curved pipe under a drain, holds water that blocks sewer air and insects. In a bathroom nobody uses, that water slowly evaporates in the Arizona heat and leaves the pipe open to the sewer. Sewer roaches are also more common where sewer lines are old, including the historic districts on our Phoenix pest control page and the older neighborhoods covered under pest control in Tempe.
When American cockroaches are most active
American cockroach numbers climb through the summer, since heat speeds up how fast the young develop. The biggest jumps often follow monsoon storms, roughly July through September, when heavy rain fills the sewers and drives roaches up through manholes and cleanouts. Our monsoon season pest surge post includes a checklist for walking the property after a storm. Activity slows in the cooler months but does not stop, since sewer lines stay fairly warm through a Valley winter.
How American cockroaches differ from German cockroaches
The German cockroach is a much smaller, tan roach that lives and breeds indoors, mostly in kitchens and bathrooms. American cockroaches seen indoors are usually visitors from the sewer or the yard, so the two species need different treatment.
| Feature | American cockroach | German cockroach |
|---|---|---|
| Size | About 1 1/2 to 2 inches | About 1/2 to 5/8 inch |
| Where it breeds | Sewer lines and underground yard boxes | Indoors, near kitchen and bathroom plumbing |
| A few seen indoors usually means | Roaches getting in from outside or the sewer | Roaches breeding inside the house |
| Treatment focus | Drains, yard boxes and the exterior | Gel baits and monitoring traps indoors |
Small roaches in kitchen cabinets call for indoor baiting, which our cockroach control page explains along with the Turkestan cockroach, a smaller roach that lives in meter boxes.
Health concerns with American cockroaches
American cockroaches travel through sewer lines and drains, where they can pick up bacteria and carry it onto kitchen counters and food. Allergens from their droppings and shed skins can also make asthma worse, especially in children. A single roach in the garage is no cause for alarm, but regular sightings indoors are worth treating, and kitchen surfaces a roach has crossed should be washed.
What American cockroach control includes
Platinum Pest Management's American cockroach control focuses on the plumbing and the outside of the house, since that is where these roaches live and get in. We use EPA-registered products, applied by licensed technicians according to the label.
- Inspection. The technician checks drains, cleanouts, yard boxes, door thresholds and the garage to see where roaches are coming from.
- Exterior treatment. We treat along the foundation and across door thresholds, where roaches cross on their way inside.
- Meter boxes and other harborage. Meter and valve boxes are treated, along with damp landscape rock near the house, since roaches rest there during the day.
- Drains and cleanouts. We check cleanout caps and treat floor drains and other little-used drains where roaches have been coming up.
- Sealing advice. The technician points out worn door sweeps and gaps around pipes, and notes which repairs a homeowner can make.
- Follow-up. On the next visit, we check whether activity has dropped and adjust the treatment where roaches still get through.
American cockroaches are covered under our general pest control service. New roaches keep arriving from the sewer system, so treatment renewed on one of our pest control plans holds up better than a single visit. Under our re-service guarantee, we return and re-treat at no extra charge when covered pests show up between scheduled visits.
How to keep American cockroaches out of the house
Homeowners can close off many of the routes American cockroaches use.
- Once a week, run water in guest bathroom drains, laundry room floor drains and any other drain that sits unused.
- Keep caps on sewer cleanouts, and replace any that are cracked or missing.
- Put door sweeps on outside doors, including the door from the garage into the house.
- Clear leaves and stacked lumber away from the foundation and meter boxes.
- Fix irrigation leaks near the house so the soil and rock along the walls can dry out.
A free inspection shows which drains and gaps the roaches are using, and the technician gives a written quote at the same visit.
Frequently asked questions
Does seeing one American cockroach mean my house is infested?
One American cockroach in a bathroom or garage usually does not mean the house is infested. It most likely came up a dry drain or walked in under a door from outside. Frequent sightings, or roaches in several rooms, suggest an open route from the sewer or a yard box, and an inspection can track it down.
Can American cockroaches fly?
Adult American cockroaches have full wings and can fly short distances, especially when temperatures are high. They are weak fliers, though, and usually run rather than fly when disturbed. Nymphs, the young roaches, have no wings and cannot fly at all.
How do I stop roaches from coming up the bathroom drain?
Keep water in the drain traps by running each sink, tub, shower and floor drain at least once a week, including those in guest rooms and the laundry room. Water in the P-trap blocks roaches coming up from the sewer, and a cover helps on floor drains. If roaches keep coming up a drain that is used every day, the trap or pipe may need a plumber's attention.
Are American cockroaches dangerous?
American cockroaches do not sting and rarely bite, but they travel through sewers and can carry bacteria onto kitchen counters and food. Allergens from their droppings and shed skins can also aggravate asthma. The risk grows with the number of roaches, so regular sightings indoors are worth treating, and surfaces they cross should be cleaned.
Is American cockroach control part of general pest control?
American cockroaches are covered under Platinum Pest Management's general pest control plans. Each visit includes exterior treatment around the foundation and door thresholds, and the technician treats meter boxes, valve boxes and drains where roaches are active. Covered pests that return between scheduled visits are re-treated at no extra charge.