Drain Fly (Moth Fly)
Family Psychodidae
Small, fuzzy, moth-like flies that breed in the organic slime lining drains and appear on bathroom and laundry walls.
- Size
- 2–4 mm
- Look
- Fuzzy, moth-like
- Breeds in
- Drain slime
- Fix
- Scrub the drain
Questions about the Drain Fly
How to identify a Drain Fly
Identification
- About 2–4 mm, grey to brown and covered in fine hairs.
- Broad, leaf-shaped wings held roof-like over the body.
- Weak, hopping flight.
Where it lives
- Shower, basin and floor drains; laundry tubs; sump pits and grease traps.
- Any wet organic film, such as under leaking fixtures.
Behaviour
- Rest on walls near drains during the day.
- Larvae live in the gelatinous film inside drains.
Why it matters
A sign that a drain needs cleaning, or that there may be a hidden leak or broken pipe. See tiny flies coming from the drain.
Commonly confused with
More questions about flies
All fly questions →Other fly species
House Fly
Musca domestica
The common grey fly found indoors worldwide. It breeds in rubbish, compost, manure and pet waste, and can carry bacteria onto food.
Blowflies
Family Calliphoridae
Large, often metallic green, blue or bronze flies that breed in meat and dead animals. A sudden swarm indoors usually means something has died nearby.
Fly guides
Common Brisbane Household Pests
A Brisbane-specific overview of the pests residents meet most often, when they are active, and what the subtropical climate, storms, creeks and Queenslander homes mean for pest pressure.
GuidePest Prevention Checklist
A printable seasonal checklist of simple, low-cost tasks that reduce pests around Australian homes, with the reason behind each step and extra lists for renters, apartment residents, pet owners and Queenslander owners.
GuideUnderstanding Pest Activity After Rain
Why storms and wet weather bring cockroaches, ants, mosquitoes and spiders into homes, what to expect in the days and weeks afterwards, and what to do before and after rain and floods.
Flies by location
More about flies
Flies
Two-winged insects that breed in rotting organic matter. House flies, blowflies, vinegar flies and drain flies each point to a different breeding source, and finding that source is the key to getting rid of them.
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Sources & further reading
- Australian Museum — insects and spiders — Australian Museum
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