How do I get rid of cockroaches?

Get rid of cockroaches by combining methods rather than relying on one product. A combination of non-chemical and chemical methods is the best strategy to eliminate and prevent cockroaches in the house.^[1] In practice that means finding where they live, taking away what keeps them alive, placing baits where they travel, and checking that the numbers are actually falling.

Start by knowing which cockroach you have

Several species live in Virginia homes: the American, oriental, German, brownbanded and smokybrown cockroaches.^[1] The two you are most likely to meet:

• German cockroach. Small, 10 to 15 mm (0.4 to 0.6 inch) long, with two parallel dark bands on the shield behind the head.^[1]
• American cockroach. Large, 2.5 to 3.8 cm (1 to 1.5 inches) long, with a light-colored shield behind the head marked with two darker reddish spots.^[1]

The species matters because the fix differs: limiting moisture can deter German cockroaches, while American cockroaches may also call for adjusting both temperature and humidity.^[2] Not every roach in the house is an indoor pest. Wood roaches turn up in piles of firewood, wet mulch and clogged gutters, and the adult males, which can fly, may be attracted to bright porch lights at night. The adult females are flightless, with shiny bodies darker than the males. A wood roach lives outdoors and cannot establish itself and reproduce in the warm, dry living space of a house.^[4][1] Your county Extension office can help identify a specimen.^[2]

Find where they are hiding

Cockroaches are mostly nocturnal, so you may find droppings, cast skins, egg cases or dead roaches before you see a live one.^[1] Seeing more of them during the day can be a sign of a large, growing infestation.^[1]

Set sticky traps flat against walls and cabinet bases in the kitchen and bathroom, under sinks, behind the refrigerator and stove, and where pipes come through walls. Tight cracks 3/8 inch or smaller are enough for a cockroach to hide in,^[2] and they follow regular runways such as a water pipe through a wall, the narrow space beside or behind an appliance, or along cabinet bases near the floor.^[1] Check the traps daily. The ones that fill fastest show you where to treat. Traps are a measuring tool, though: sticky traps alone are unlikely to control a cockroach population.^[1]

Take away food, water and shelter

Cockroaches can also carry germs on their bodies onto food, so good sanitation helps prevent foodborne illness.^[1] Baits work far better when the roaches have nothing else to eat. Indoor baits tend to be most effective after the house has been thoroughly cleaned and food and water sources removed.^[1]

• Wash dishes before bed, wipe counters, and clean grease and crumbs from around and under the stove and other appliances.
• Store dry food in sealed containers, because cockroaches can chew through paper, cardboard and thin plastic.^[2]
• Put pet food and water away overnight.
• Fix drips and leaks at sinks, toilets, the water heater and pipes; cockroaches must have water to survive.^[1]
• Vacuum cracks and crevices at least weekly, and seal the vacuum bag in another bag promptly.^[2]
• Clean droppings with hot, soapy water, which also removes the aggregation pheromones that draw more roaches to the spot.^[1]
• Get rid of spare cardboard boxes, stacks of paper and piles of laundry, which give roaches ideal places to hide.

Use baits where they travel

Gel and paste baits come in syringes so you can place small amounts in runways, harborages, cracks and crevices.^[1] Put small dabs or bait stations where the traps caught the most roaches, keep them where children and pets cannot reach them, and follow the label. Never put insect baits where small children can find them, pick them up and put them in their mouths.^[5] A few details make the difference:

• Keep baits in place continuously until the population drops, and replace them when they dry out.^[1]
• Do not spray aerosol or liquid insecticides near baits; sprays can repel cockroaches from the bait.^[1]
• Small stations made for German cockroaches may not let larger American cockroaches in. Throw away empty stations, which can become hiding places themselves.^[1]
• If a bait stops working, switch to a different brand or a product with a different active ingredient, since some cockroaches resist certain pesticides or avoid certain baits.^[2]

Insect growth regulators, sold as sprays, gel baits and small devices, interfere with how young cockroaches develop: they do not kill quickly, but the population declines over months because the insects cannot reproduce.^[1] Boric acid, silica gel or diatomaceous earth dust, puffed as a thin, barely visible layer into cracks and behind cabinets, works in clean, dry places and must be reapplied if it gets damp.^[1]

What to skip

• Bug bombs. Foggers penetrate cracks and cluttered areas only so far and seldom eliminate a population.^[1] Their aerosol propellants are typically flammable, and improper use may cause a fire or explosion.^[6]
• Ultrasonic plug-ins. Many research studies have shown that ultrasonic devices do not repel or kill cockroaches.^[1]
• Borax, baking soda and baking powder. They do little to reduce cockroach populations and are often confused with boric acid, which is recommended for cockroach control.^[1]
• Spraying everything. Some pesticides might repel cockroaches rather than kill them, which can chase them into other rooms or into the apartment next door.^[2]

Keep them out afterwards

Seal holes where pipes and wires come through walls with caulk, expandable foam or tightly packed steel wool, and caulk the gaps along baseboards and between cabinets and walls.^[1] Fit door sweeps and keep weatherstripping in good shape. Run faucets and flush toilets you rarely use, because cockroaches can enter through dry drains.^[1] Check grocery bags, packages and other containers before bringing them inside.^[3] Keep cleaning even after the roaches are gone, since their allergens persist.^[1] For a fuller routine, see how to keep cockroaches out of an apartment, and if they keep appearing in a tidy home, read why roaches show up in a clean house.

Stop and call a pro if

• Traps keep filling after several weeks of steady baiting and cleanup, or you see roaches in daylight.
• You live in an apartment, townhouse or condo and the roaches are coming through shared walls or plumbing. In multifamily housing, pests in untreated units can spread back to treated ones, so the building needs a coordinated plan.^[1]
• Someone in the home has asthma or allergies. Cockroach secretions, droppings and body parts can trigger allergies and asthma in some people.^[1]
• A child or pet swallows bait or dust, or anyone feels ill after a pesticide is used. If the person is unconscious, having trouble breathing or having convulsions, call 911. Otherwise, read the label's first-aid instructions and call the poison center at 1-800-222-1222. For a pet, the National Pesticide Information Center (1-800-858-7378) also answers questions about animal poisonings.^[5]
• You are tempted by a fogger or a stronger product. Pest control operators may have specialized equipment and professional-use materials that unlicensed homeowners cannot buy,^[1] and in Virginia no one may apply or recommend a pesticide commercially without a pesticide business license and a certified commercial applicator on staff.^[7]

Getting help on Loclis

Whether to do it yourself or hire an exterminator covers the choice in more detail, and what cockroach extermination costs in Virginia explains what goes into a quote. Browse cockroach control services, find pest control around Blacksburg or read more pest control answers. When you are ready, describe the job on Loclis so licensed pest control businesses can quote it.