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How to Kill Waterbugs With Boric Acid

Joshua Duvauchelle

The cockroach (Blattaria), also known as a waterbug, is a common insect pest found in homes throughout North America. The most common species is the American cockroach, but several thousand others exist and may be found in your house.

The insects not only feed on food in your home, but may also carry dangerous diseases. Use boric acid to kill the waterbugs and rid your home of the pests.

  1. Locate household areas in which you have a waterbug problem. Note places that need to be treated with boric acid. Common infestation areas include your kitchen and bathroom. Roaches like to hide in dark, secluded areas like kitchen cabinets and behind appliances such as your stove and refrigerator.

  2. Use boric acid powder, which typically comes in a handheld shaker and is available at most department stores. Shake the powder into the corners of your kitchen cabinets, behind appliances and in any other areas that you noted. Apply a thin, even layer of powder that is barely perceptible, as even a small amount is highly toxic to waterbugs.

  3. Use boric acid paste as an alternative to the powder. The paste is easier to apply and manage in small areas. Squeeze the paste into wall cracks and crevices and other crawl spaces in which you've noticed waterbugs.

  4. Place roach bait near the boric acid as an optional efficacy booster. The bait will attract the waterbugs through the boric acid, creating a double-pronged killing strategy to effectively eliminate most waterbugs in your home.

  5. Wait. The boric acid will kill roaches within seven to ten days of contact. Reapply the powder every ten days if you continue to notice waterbugs in your house.

  6. Tip

    Keep your home clean to avoid attracting roaches. Boric acid doesn't repel waterbugs. The insects will continue to return to the treated area, making the product effective for long-term killing and control of roaches.


    Keep boric acid away from countertops and areas in which you may have food intended for human consumption.