Drain Fly

Natural Habitat

Moist environments high in organic matter, such as drains, sewers, septic tanks, and damp soil.

Diet & Feeding

Larvae feed on the organic slime (biofilm) found in drains; adults primarily feed on liquid carbohydrates like nectar and contaminated water.

Behavior Patterns

Poor fliers that often crawl or hop; they are most active at night and tend to rest on walls near their breeding sites. Life cycle can be completed in 7 to 20 days.

Risks & Benefits

Generally harmless to humans but can be a nuisance and potentially transport bacteria from drains to food surfaces. Larvae play a minor beneficial role by breaking down organic matter in sewage systems.

Identified on: 1/1/2026