Fruit Flies Vs. Drain Flies

Differences Between Drain & Fruit Flies

As you are reading this, your kitchen – or worse, your house – may be under siege by tiny flying insects. And while you can often fight off fruit flies quite easily, that will not always be the case.

So with flying insects looking incredibly similar, here is a small guide to tell you the difference between the fruit flies or drain flies – also dubbed gnats. In other words, this article will tell you whether you should be running towards or from the flying insects in your house.

Fruit Flies


These flies are very distinct from all other types of flies, but due to their small nature, they are often indistinguishable. They are also the most common flying insects to appear inside your kitchen. They come in two very distinct colors.

The red-eye fruit fly has red eyes with a striped abdomen, and carries a very bright color on its body. Dark-eyed fruit flies only differ in terms of their eye color and are pretty much the same. 

They can often be inside your drain, near a trash can, or even buzzing around you. They are harmless and are more of a nuisance than anything else. Fruit flies do not bite humans or animals either.

Drain Flies


Drain flies are also a very different type of flying insect as they tend to stay in damp and mostly dark places such as drains. Unlike most flies, these drain flies have “fur” on their wings, heads, and along their antennae. They carry a tan or light gray color on their bodies, and their wings have very distinguishable borders and are shaped like a heart.

They breed in these dark and damp places, and can sometimes clumsily fly out and land onto the floors and walls. They are also completely harmless but can aggravate asthma among certain people.

Here are some of the key differences between regular fruit flies and gnats that you can easily recognize.

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Traveling Together

Fruit flies very rarely stay together in larger groups, but gnats will always swarm a waste together. So unless you have a big bowl of fruit out in the open, you won’t be noticing more than a few of these fruit flies. On the other hand, if you see a massive swarm of insects inside your kitchen, they may be gnats.

Swarming Near Food

Fruit flies almost always feed on rotting fruits, usually in the kitchen area. Females lay their eggs on the surface or inside fruit that’s overripe, or decaying. Drain flies only feed on whatever ferments inside your drain.

They are not particularly picky eaters and don’t come out of their hiding places when there is light outside. Fruit flies don’t mind the light as much and can come out at any time of day.

Fruit Flies Don’t Fly Far

As we mentioned earlier, fruit flies are lone hunters and only congregate when there is a lot of fruit in a specific place. So they don’t tend to go far from their food source, which is usually the kitchen.

While drain flies can inhabit your kitchen, you can help rule them out by removing fruit and garbage from the premises. If the flies disappear, they were most likely fruit flies. If the flies persist not matter how clean your counters, garbage or floors are, then you may have drain flies.

Article Reviewed By:

Dakota S. MS in Biology

Dakota holds a Masters of Science in biology/biological sciences, with an emphasis on entomology and parasitology. An accomplished researcher and writer, Dakota has completed numerous research papers and published peer-reviewed literature. Notable accomplishments include the study and documentation of new structures not previously known to be fluorescent in Ixodida (ticks).

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