Drain Flies
NuisanceWhat it is
Tiny fuzzy, moth-like flies that breed in the organic film inside drains, floor drains, sewage areas, and other wet sites. Persistent adults usually indicate a nearby moist breeding source.
How to recognize it
Fuzzy, moth-like flies about the size of a gnat resting on walls near sinks, tubs, and floor drains.
Where you will find it
The slime layer inside drains, floor drains, and sewage areas.
Why it matters
Seeing adults usually means a breeding source in or near a drain.
What to do
- Remove food waste, rinse bins and recycling, and keep trash covered.
- Clean up spills and organic buildup around drains, sinks, and floor areas.
- Note where the flies gather. The location helps a technician find the breeding source.
- Contact a licensed pest professional to find and address the source, since killing adults does not stop the cycle.
When to call a professional
- Flies keep returning after you clean.
- You suspect a drain, sewage, or hidden food source.
- You run a restaurant or food facility.
Related pests
Black Flies
Small, dark, hump-backed flies whose females may take blood meals from people and animals. They usually breed in clean, flowing water and are most troublesome outdoors near streams and rivers.
Read more →Blow Flies
Metallic or dull-colored flies that commonly breed in carrion, animal waste, garbage, or other decomposing organic matter. Indoor activity can indicate a sanitation problem or a dead animal nearby.
Read more →Crane Flies
Long-legged flies that resemble oversized mosquitoes but generally do not bite. Adults are often attracted to lights, while larvae usually live in moist soil, turf, or decaying organic matter.
Read more →Flies
A broad group of two-winged insects. Pest flies may breed in food waste, drains, manure, carrion, standing water, or other organic material and can be important sanitation indicators.
Read more →This page is general information, not a diagnosis. Pests vary by region and situation, and an on-site inspection is the reliable way to know what you have.