Bug Identifier
Comparison

Fruit Fly vs Drain Fly

By the Bug Identifier Editorial Team. Updated September 27, 2026. 3 minute read.

Fruit Flies and drain flies are easy to mix up at a glance, but a few details separate them quickly. Here is how to tell which one you found and what, if anything, you should do about it.

Quick answer

Check for this first. A fruit fly has very small tan body with bright red eyes, while a drain fly has fuzzy, gray, leaf-shaped wings held roof-like over the body.

Side-by-side comparison

Fruit FlyDrain Fly
GroupFlies & MosquitoesFlies & Mosquitoes
Scientific nameDrosophila melanogasterClogmia albipunctata
Size2–4 mm2–5 mm
ColorsTan, Brown and RedGray and Black
Legs6 legs6 legs
WingsYesYes
Bites or stingsNoNo
RiskNuisanceNuisance
Key featureVery small tan body with bright red eyesFuzzy, gray, leaf-shaped wings held roof-like over the body

Key differences

  • Color: Fruit Flies are tan, brown and red; drain flies are gray and black.
  • Where found: look for fruit flies in the kitchen; drain flies turn up in the bathroom, in the kitchen and in basements and garages.
  • Signature feature: Fruit Flies: very small tan body with bright red eyes. Drain Flies: fuzzy, gray, leaf-shaped wings held roof-like over the body.

How to identify fruit flies

A tiny, tan fly with bright red eyes that hovers over ripe fruit, drains, trash and spilled drinks. It can go from egg to adult in about a week.

  • Very small tan body with bright red eyes
  • Slow, hovering flight around produce
  • Gathers around fermenting fruit, wine and vinegar

See the fruit fly profile

How to identify drain flies

A small, fuzzy, moth-like fly that rests on bathroom walls near sinks, tubs and floor drains. Its larvae live in the slimy film inside drains.

  • Fuzzy, gray, leaf-shaped wings held roof-like over the body
  • Short, weak, hopping flight
  • Found near drains, especially in bathrooms

See the drain fly profile

Which one is more dangerous?

Neither is more dangerous than the other; both are rated nuisance on our scale.

Fruit flies don't bite; they can carry bacteria from trash onto food. Drain flies don't bite and aren't known to spread disease in homes.

Where and when you'll see each

Fruit Flies turn up in the kitchen, mostly in spring, summer and fall. Drain Flies turn up in the bathroom, in the kitchen and in basements and garages, mostly in spring, summer, fall and winter.

Because they share habitat, you may find both in the same place, so check each individual.

What to do if you find one

Fruit Flies: Refrigerate or toss overripe fruit and rinse recyclables. Read the full removal guide for more.

Drain Flies: Scrub drains with a stiff brush to remove the organic film. Read the full removal guide for more.

Biology: flies & mosquitoes

Flies have only one pair of working wings; the second pair is reduced to small balancing knobs called halteres. They go through complete metamorphosis, and the larvae, called maggots, need moist organic material such as garbage, soil, drain film or standing water.

Frequently asked questions

What is the main difference between fruit flies and drain flies?

Color: Fruit Flies are tan, brown and red; drain flies are gray and black.

Which is bigger, a fruit fly or a drain fly?

Fruit Fly: 2–4 mm. Drain Fly: 2–5 mm.

Do fruit flies or drain flies bite?

Fruit Flies do not bite. Drain Flies do not bite.

Where are they usually found?

Fruit Flies: in the kitchen. Drain Flies: in the bathroom, in the kitchen and in basements and garages.