Drain flies
Small fuzzy flies that sit flat on bathroom walls. They breed in the slime inside a drain, so the fix is a brush, not bleach.
- Size
- Small, a few millimetres
- Colour
- Grey or brown, fuzzy, wings like a moth's
- Lives
- Sinks, showers, overflows, floor drains
- Active
- Rest by day, flutter when disturbed
How to tell
Fuzzy, moth like wings
Broad, rounded wings held flat over the body, like a tiny moth.
Sit and barely move
They rest on tiles and make short hops when you get close.
Not a fruit fly
Fruit flies are tan with red eyes and hover round the fruit bowl.
Signs you have them
- Flies on bathroom walls near the sink, bath or shower.
- A slow drain or one that is rarely used.
- Flies on the tape over a plughole after a night with tape on it.
- Back within hours of bleach or boiling water.
The plan
- 1
Find the drain
Clear tape over each plughole overnight. Flies on the tape show which one.
- 2
Scrub the pipe
A long drain brush, up and down the pipe and the overflow.
- 3
Then an enzyme cleaner
Last thing at night, as its label says, to clear the film.
- 4
Keep it running
Run water through rarely used drains every week.
What people worry about
Why does bleach not work?
The eggs and larvae live in a slime film on the pipe wall. Bleach rushes past it. Scrubbing the pipe is what clears them.
Are drain flies harmful?
They do not bite. They are a sign of a drain that needs cleaning, and they go once the film is gone.
Fruit flies or drain flies?
Drain flies are grey and fuzzy and sit flat on bathroom walls. Fruit flies are tan, often red eyed, and hover round fruit and bins.