Drain Fly Larva (Psychodidae)

Natural Habitat

Aquatic or semi-aquatic environments, often found in the gelatinous films of drains, sewage pipes, septic tanks, compost, and other decaying organic matter with consistent moisture.

Diet & Feeding

The larvae feed on fungi, bacteria, algae, and other decaying organic matter found in the slime layers of their habitat.

Behavior Patterns

Drain fly larvae are often seen wriggling in the moist film. They are non-mobile for significant periods, primarily staying within their food source. They go through several instars before pupating into adult drain flies, which are small, furry, moth-like insects.

Risks & Benefits

Potential risks include being a nuisance pest indoors, especially in bathrooms and kitchens. In large numbers, they can indicate issues with drain cleanliness or plumbing. While generally not directly harmful to humans (they don't bite or transmit diseases), their presence can be indicative of unsanitary conditions. They are also known to cause bronchial asthma in sensitive individuals due to airborne particles of dead flies or larval casings. Benefits are minor, mainly contributing to the decomposition of organic matter in their natural outdoor habitats.

Identified on: 11/27/2025