Drain Fly

Natural Habitat

Damp environments with decaying organic matter, such as drains, sewage treatment plants, septic tanks, and wet soil.

Diet & Feeding

Larvae feed on the nutrient-rich slime (biofilm), bacteria, and fungi found inside plumbing pipes. Adults feed on liquid carbohydrates and water.

Behavior Patterns

Poor fliers that often crawl on surfaces or take short, hopping flights. They are most active at night and are frequently seen resting on walls in bathrooms or kitchens near drains.

Risks & Benefits

Generally harmless to humans and do not bite or sting. However, in large numbers, they can be a nuisance and may potentially transport surface bacteria from drains to food preparation areas. In the ecosystem, they are beneficial as decomposers that help break down organic waste.

Identified on: 3/11/2026