Flies & gnats

Drain flies: identification & drain fly control

Also known as: moth flies, sewer gnats, filter flies

Drain flies breed in the organic film inside drain lines and floor drains. We identify the active drains, apply enzymatic cleaners that digest the film and treat harborage around the fixtures.

Tiny fruit flies and gnats gathered on ripe fruit in a kitchen

How to identify drain flies

What it looks like
Small fuzzy gray-brown flies with rounded, moth-like wings held roof-like over the body.
Size
1/8 inch
Where you'll find it
Sink and floor drains, showers, sewer lines, septic and grease traps.
Commonly confused with
Fruit flies are smooth-bodied with red eyes.

Signs of drain flies in your home

  • Flies resting on bathroom walls
  • Activity increasing at night
  • Flies appearing after a drain sits unused

Drain flies questions homeowners ask

How do I find which drain has flies?

Tape a clear cup or plastic over each drain overnight — the drain with flies stuck to the tape is the breeding site.

Drain fly control by city

Local technicians handle drain flies in every market below — pick your city for neighborhood coverage, seasonal notes and a free quote.

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