The main reason we don’t treat for fruit flies or gnats is because they are breeding from an organic source. This could be food but also areas of moisture. So even if we sprayed or treated to kill them, they would still be multiplying and return to bother you.

Fruit flies are smaller than house flies, and have red eyes. They appear tan in color and are no larger than an 1/8 of an inch long.

Fruit flies are often around ripened or decaying fruit and vegetables, but they can also breed in drains, on dirty mops or rags, in recycling bins, trash cans, soil, and other areas of moisture and decay.

In order to manage fruit flies, you need to find the source. Once you have eliminated the source, it’s important to keep fruit and veggies either in the refrigerator or a brown bag for a couple weeks or you will attract them back into the home.

If you’re still seeing fruit flies after that, check your drains. One trick is to put tape over half the drain overnight. If flies are stuck to it, you know they are breeding in the organic matter that lines the drains. There are enzymatic drain cleaners that will help remove that “gunk” inside. Bleach, boiling water, and other products will only kill the larvae in the drain now; it does not keep the adults from laying more eggs.

If the enzymatic cleaner doesn’t handle it, a more thorough method is to shut off the water and take apart the s-trap or u-shaped pipe area and scrub it thoroughly – but this is obviously more work and may require a plumber.

If you have potted plants, they can also be in the soil. Check by digging, or placing the plant in a small enclosed space overnight. It’s easier to re-pot the plant, but at the minimum, don’t over water and allow the soil to dry out. You can also use gravel or rocks for the top 1 to 2 inches of the pot to discourage flies/gnats from getting into the soil.