Drain fly (moth fly)

Indoors near drains, sinks, and other damp areas where organic film accumulates.

Larvae feed on microbes and decaying organic matter in drain slime; adults generally take little or no food.

Adults are weak fliers and often rest on nearby walls. Larvae develop in wet biofilm; recurring adults usually indicate a nearby breeding site.

Harmless to people and do not bite or transmit disease; large numbers can be a nuisance and may signal dirty or clogged drains.