Have you noticed tiny, fuzzy insects resting on your bathroom walls or hovering around the sink or shower? They may look like fruit flies or tiny moths, but they are often drain flies, also called moth flies. Their presence can be a clue that something is building up inside your plumbing.

Drain flies are small, grayish or brown insects with fuzzy wings and a moth-like appearance. They are weak fliers and commonly rest near sinks, showers, bathtubs, and floor drains. Although they are generally not considered a significant health threat, they can multiply quickly when their breeding source remains untreated.

So why are they attracted to your bathroom? Drains provide moisture, warmth, and organic material. Inside pipes, a slimy layer called biofilm can accumulate from hair, soap residue, bacteria, and other organic debris. Drain flies lay their eggs in this material, where their larvae develop.