Drain Fly

Natural Habitat

Found in moist environments rich in organic matter, such as drains, sewers, septic tanks, and damp soil.

Diet & Feeding

Larvae feed on the gelatinous film of bacteria and organic debris found in drains; adults primarily consume liquid carbohydrates like nectar and polluted water.

Behavior Patterns

Weak fliers that are often found resting on walls near drains. They are most active at night and go through a complete metamorphosis (egg, larva, pupa, adult) in about two weeks.

Risks & Benefits

Generally harmless as they do not bite or transmit diseases to humans. However, large infestations can be a nuisance and may indicate a plumbing issue or clogged drain.

Identified on: 5/15/2026