Small flies appearing in a kitchen or bathroom are often described as fruit flies, but they may actually be drain flies. Although both insects can become indoor pests, their appearance, behaviour and breeding sites are different.
Correct identification is important. A sticky fruit fly trap can catch adult fruit flies, but a drain fly infestation usually requires attention to the organic material developing inside a drain or waste pipe.
WHAT DO FRUIT FLIES LOOK LIKE?
Adult fruit flies are small, compact flies that usually measure approximately 3–4 mm long. They are commonly pale brown or yellow-brown and may have distinctive red eyes when examined closely.
They look similar to miniature versions of familiar house flies, although they are considerably smaller.
Fruit flies tend to fly around actively and may gather in groups around fruit, drinks, bins and food waste.
WHAT DO DRAIN FLIES LOOK LIKE?
Drain flies are also small, but they have a noticeably different shape. Their broad, hairy wings give them a fuzzy or moth-like appearance.
When resting, drain flies often hold their wings over their body like a roof. They may appear grey, brown or almost black.
Drain flies are generally weaker flyers than fruit flies. They often make short, hopping flights and rest on walls or tiles close to sinks, showers and drains.
WHERE ARE THE FLIES GATHERING?
The location of the activity can provide one of the strongest identification clues.
Fruit flies are normally found around:
- Fruit bowls
- Ripe or damaged produce
- Kitchen bins
- Food waste containers
- Recycling
- Wine, beer and sugary drinks
- Empty bottles and cans
Drain flies are more commonly found around:
- Kitchen and bathroom sinks
- Shower drains
- Floor drains
- Utility room drains
- Waste pipes
- Persistently damp areas
WHERE DO FRUIT FLIES BREED?
Fruit flies lay their eggs near moist, fermenting organic material. This provides food for the larvae after they hatch.
Typical breeding sources include overripe fruit, food residue, dirty bins, recycling containers and fermenting liquids. Even a small amount of hidden residue can support an infestation.
Removing this material is essential. Catching adult fruit flies without removing the breeding source will not prevent more flies from emerging.
WHERE DO DRAIN FLIES BREED?
Drain fly larvae develop in the moist organic film that can accumulate inside drains, waste pipes and other persistently damp areas.
The visible adult flies may rest on nearby walls, but the breeding source is often below the surface inside the drainage system.
Pouring a general cleaning product down the drain may not remove the entire organic film. The drain and accessible components may need to be cleaned thoroughly to remove the material supporting the larvae.
HOW TO CHECK FOR FRUIT FLIES
Observe whether the insects gather around ripe fruit, food waste or fermenting drinks. Inspect fruit bowls, bins, recycling and food storage areas for hidden residue or damaged produce.
Position a sticky fruit fly trap near the area of greatest activity. If the trap catches small, compact flies and activity is centred around food, fruit flies are the likely cause.
HOW TO CHECK FOR DRAIN FLIES
Look for small, fuzzy flies resting on tiles or walls close to a drain. They may become more noticeable when the area has been undisturbed.
Clean the visible drain components and continue observing the area. Persistent activity concentrated around one plughole or drain suggests that organic material may remain inside the pipe.
Where a drainage fault, leak or inaccessible breeding site is suspected, professional inspection may be necessary.
FRUIT FLY AND DRAIN FLY DIFFERENCES
| FEATURE | FRUIT FLIES | DRAIN FLIES |
|---|---|---|
| Appearance | Small, compact fly | Fuzzy and moth-like |
| Typical colour | Pale or yellow-brown | Grey, brown or dark |
| Common location | Fruit, bins and fermenting drinks | Sinks, showers and drains |
| Breeding material | Fermenting food and liquids | Organic film inside drains |
| Flight | More active flying | Short, weak or hopping flights |
HOW TO GET RID OF FRUIT FLIES
- Dispose of overripe or damaged produce
- Clean fruit bowls and food storage areas
- Empty and wash kitchen bins
- Rinse recycling before storage
- Clean sugary and fermented drink spillages
- Use sticky fruit fly traps to catch remaining adults
HOW TO GET RID OF DRAIN FLIES
- Identify the drain producing the flies
- Remove hair, sludge and accessible debris
- Clean the plughole, overflow and drain components
- Address leaks and persistently damp areas
- Continue cleaning until the organic breeding film is removed
- Seek professional assistance if the source is inaccessible
FREQUENTLY ASKED QUESTIONS
Are fruit flies and drain flies the same insect?
No. They are different flies with different appearances, breeding materials and preferred locations.
Do fruit fly traps catch drain flies?
A sticky trap may catch some adult drain flies, but it will not remove the organic material inside a drain where the larvae are developing.
Why are small flies appearing around my sink?
They may be attracted to food residue around the sink, or they may be drain flies breeding inside the waste pipe. Examine their appearance and where they spend most of their time.
Can I have both fruit flies and drain flies?
Yes. A property can contain several suitable breeding sources, so more than one type of small fly may be present.
When should I use a sticky fruit fly trap?
Use one when small flies are gathering around ripe fruit, food waste, bins, recycling or fermenting drinks. Always remove the breeding material as well.
