Drain flies, also known as moth flies or sewer gnats, are tiny, fuzzy insects commonly found in moist, decaying organic matter. These small flies, 1.5mm-5mm long, are characterized by their dark wings covered in hair-like scales, giving them a moth-like appearance. Though they are not harmful to humans, their presence can indicate underlying issues with plumbing or sanitation in your home. Drain flies breed and thrive in areas where stagnant water, organic debris, and bacteria accumulate, making them frequent visitors to kitchen sinks, bathroom drains, and other areas with poor drainage.

The life cycle of a drain fly is rapid, with eggs hatching in less than two days and adults emerging within two weeks. This quick reproduction can lead to large infestations if the breeding grounds are not addressed. Common problem areas include clogged or slow-moving drains, leaking pipes, and even standing water in unused toilets or showers. Homeowners often notice these flies hovering around drains, particularly in bathrooms and kitchens, where they can become a persistent nuisance. The flies are most active during the evening and night, when they can be seen resting on walls or around light sources.