If you’ve ever seen those pesky, dark winged gnats that fly around drains, then you know what a nuisance they can be – especially when they are in your home or office. These gnats, also called drain flies or moth flies, don’t bite, and tend to congregate around standing water such as drains or toilets that are not used often.
For the most part, drain flies are fairly easy to get rid of; pests invade a home looking for either food, harborage or a place to breed. In this case, the larval drain flies cannot survive without moisture and standing water provides that. In fact, they can live just about anywhere that has standing water for as little as a week. They will seek out the water, breed and then more drain flies will emerge until you have an infestation.
In a minor infestation such as returning from vacation to find drain flies breeding in the standing water in your toilet, killing the adults with a commercial insect spray or using a fly swatter is sufficient. However, if the flies keep returning then it is necessary to determine their breeding area and correct it. Often it is a drainage problem in a pipe or the floor or the drain pan under the refrigerator.
The larvae are very small and difficult to see so correctly identifying the breeding site can be a challenge. To find the point of entry that the flies use, use petroleum jelly or vegetable oil to lightly coat the inside of several plastic cups. Place the cups, inverted, over the drains and leave them for several days. This will capture any adults as they emerge and allow you to zero in on the breeding sites.
Figuring out how to get rid of drain flies isn’t that difficult. Once you have identified the breeding site you can begin eradication of the population. First, remove the water and clean the area thoroughly so the site is no longer functional for their purpose. Then apply a product to kill that adults and larvae. There are several products on the market for DIY fly control.
Drain flies don’t have to be a problem. As long as you avoid having standing water around and keep your drains clean you should be able to easily keep them at bay.