3 Small Black Flying Bugs In The House, Not Fruit Flies

Fungus gnats, drain flies, and phorid flies are three common small black flying bugs in the house, not fruit flies.

These tiny flying insects don’t bite but are annoying insects in the house.

However, tiny black flying bugs, such as biting midges (no see ums) and mosquitoes, that bite and itch, can also be present in the house if there are sources that draw these fruit fly-like flies.

Many people need help to differentiate between fruit flies and their lookalikes.

As an entomologist, I’ll help you identify these flies in layperson terms and provide a step-by-step guide to get rid of these flies.

Let’s dive in.

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Fungus Gnats – Identification and Source

An adult fungus gnat is black, with two pairs of dark wings with veins on them, and has long legs and a pair of long antennae.

Fungus Gnats - Small Black Flying Bugs In The House, Not Fruit Flies

It looks like a mosquito, but fungus gnats don’t bite. Their flight pattern is short and zig zag, whereas fruit flies are able fliers and fly in a straight line.

The short flight path make fungus gnats appear more as jumping bugs rather than as flies.

Outdoors fungus gnats lay eggs in wet soil beds and in decomposing organic matter such as leaf litter and containers such as compost bins and garbage disposals.

These flying bugs sneak indoors through the open windows. Any small crack on the window sills is good enough for them to fly inside the house.

The glowing light bulbs in the house also attracts them, making them fly inside the house.

Once inside, fungus gnats will lay eggs in the wet soil beds of potted plants, inside drains, and even in the food wastes stuck in appliances like dishwashers and coffee makers. That leads to a fungus gnat infestation in the house.

The fungus gnat larva is a tiny white worm with a black, dot-like head that hatches out of eggs. These worms are harmless and feed on the molds and fungi that form on the soil beds and other organic wastes in the house.

However, the larvae can feed on the plant roots, leading to declining plant health.

The maturity period from eggs to adult fungus gnats ready to breed is short.

At room temperature with the right amount of humidity, the fungus gnat eggs will hatch in 3 days, producing the larvae. The larvae go into the pupae life stage in 10 days. And it only takes 3-4 days for the adult gnats to appear from the pupae.

A single female adult fungus gnat can lay up to 200 eggs. With this short maturity period of only two weeks, you notice a sudden appearance of fungus gnats in the house.

Drain Flies – Identification And Source

Drain flies, also known as sewer flies (because they live in drain wastes) or moth flies (because they look like tiny moths), are small dark gray flies that are 1/8 inches in size.

Drain Flies

Drain flies are soft-bodied with hairy bristles on their wings, giving them a fuzzy appearance.

Drain flies lay eggs in the waste that blocks the drains. Homes with sewer, organic garbage, and plumbing defects always have a drain fly problem.

Drain flies pop out of pipes’ crevices or from the sinks’ drain holes. If you notice tiny black flies on the sink or walls of your bathroom or kitchen, chances are these drain flies.

The drain fly larvae, tiny off-white worms with a thin layer of hair, feed on the drain wastes.

These larvae, also known as drain worms, can pop out of the drain holes to feed on the waste on the kitchen floor and the shower grout.

Like the fungus gnats, drain flies also appear suddenly because of their short maturity periods.

Phorid Flies – Identification And Source

Phorid flies

Phorid flies are tiny black flies with light brown and yellow combination on their bodies. They look like house flies, but they’re small flies that are tinier than the house fly.

Phorid flies grow between 1/32 and 1/4 inches. Their oval-shaped bodies may make them look like fruit flies.

However, there are some differences. The first is that phorids have a hump in their thoraxes, which is the reason they are also known as humpbacked flies. They also have hairy bristles covering their heads.

The second difference is that phorid flies scoot or scuttle across the surface drunkenly (not in a straight line) before they take off. This behavior is easy to notice and is one of the differentiating factors between fruit flies and phorid flies.

Phorid flies lay their eggs in filthy, decaying organic material such as animal feces and even in corpses of birds and animals. They can also lay eggs in decaying plant matter.

Phorid flies enter homes through open windows and doors. Their presence in the house and the outdoors is a clear sign that there are active breeding grounds for these flies on your property.

Phorid flies inside the house will lay eggs in damp areas or moist places around the plumbing and drains in the bathroom, kitchen, basement, and laundry room.

Phorid flies, like the house fly, can spread diseases. These flies carry disease-causing bacteria on their bodies because of their association with animal wastes and corpses.

They can transfer these bacteria to your food, leading to food poisoning and other food-borne diseases.

Fruit Flies – Identification And Source

Fruit flies

Now that you know what all the small black flying bugs in the house, not fruit flies, look like, it’s time to figure out what fruit flies look like.

Knowing the anatomy of fruit flies will nail it, and you’ll be able to correctly identify which small flies you’re dealing with in the house.

Fruit flies are tiny, oval-shaped flies with stout bodies that grow up to 0.125 inches in size.

They’re not black. These flies are yellowish or tan, with blackish hues on the abdomen and a pair of tiny red eyes. A pair of fully developed transparent wings makes them able fliers.

Fruit flies also lay eggs in rotting organic matter, such as decaying plant matter, overripe fruits, wet soil, and food waste in the outdoor garbage disposal. 

These flies enter homes by picking up the scents of ripe fruits and vegetables you keep in the open.

Fruit flies in the house will lay eggs in them. These eggs produce tiny white worms in fruits, also known as maggots.

However, a home with no fruits can also have fruit flies.

Choked drains, food waste in the kitchen trash bin, and soil beds of indoor potted plants are sources of fruit fly infestation in the house with no fruits. 

Fruit flies can also get inside the fridge by getting attracted to the smell of water in the refrigerator pan.

How To Get Rid Of Small Black Flying Bugs In House, Not fruit flies

Removing these flying bugs’ breeding grounds, killing the adult flies, and preventive measures to stop these flying bugs from coming back eliminate these tiny flies.

Here’s how to do it –

Remove Decaying Organic Matter From Your Yard

Rotting leaf litter, food waste in the trash cans, pet feces, dead insects and rodents, slime spilling from broken pipes, and debris in the catch basins are all breeding grounds for these flies.

Getting rid of these wastes will remove the egg-laying grounds of these flies from your outdoors.

Fix Leaking Pipes

Leaking pipes both outdoors and indoors increases the dampness level of your home.

Water leakages and stagnant water in the yard create moist soil, attracting gnats to lay eggs. Keeping the yard soil dry prevents gnats from laying eggs on it.

Also, plumbing issues underneath sinks, bathroom fixtures, and the sump pump in your basement create moist environments that draw flies and make them lay eggs.

Keep The Drains Clean

The gunk and slime choking the drains is a breeding ground for drain flies, fungus gnats, and fruit flies. Use a drain cleaner to clean your kitchen, bathroom, and shower drains.

Cleaning the drains will kill gnats and their larvae inside the drains. That’ll drastically reduce the gnat infestation in the house.

You can also pour baking soda and white vinegar mixed with hot water inside the drains to clean them and kill the eggs and larvae of flies.

Clean The Kitchen Appliances

Appliances such as dishwashers, refrigerators, and coffeemakers can be the hidden breeding grounds for gnats.

These gnats will enter these appliances and lay eggs in the food waste stuck in them. These food wastes develop molds, food sources for the larvae or maggots.

Use Sticky Fly Traps

Many sticky fly traps are available that help lure and entrap the flies. Keep them in the areas of your home where you’ve noticed flying bugs and on the entry points, such as the windows, kitchen, and near potted plants. 

Yellow sticky traps for fungus gnats

You can also prepare a homemade fly trap with the help of apple cider vinegar, dish soap, plastic wrap, and a shallow pan.

Take the shallow pan or a bowl, and make it half full with the vinegar. Then, add a few drops of liquid dish soap.

Mix it well, cover the pan with a plastic wrap, and affix it with a rubber band. Poke a few holes into it and keep the vinegar trap where you consistently spot gnats in your home.

DIY Vinegar Trap For Small Flies In The House

The fruity smell of the vinegar trap lures the gnats. And when they sneak inside the trap through the holes in the wrap, the viscous dish soap in the pan drowns them.

It’s a great trick to kill gnats naturally. But you’ll need to keep it for a few weeks for maximum effect.

Treat The Soil of Potted Plants

The damp soil of house plants is an egg-laying ground for fungus gnats and fruit flies. Treat the soil by drenching it with a mixture of 3% hydrogen peroxide solution and water.

Hydrogen peroxide will kill the gnat larvae and gnat eggs. The mixture also helps in keeping gnats away from the plants.

Let the solution sit for a few hours to do its work. Then, remove the soil’s layer and replace it with new soil.

Another trick is to scatter Epsom salt on the soil. It kills the gnat eggs and larvae.

Seal Gaps On The Windows

The cracks on the window sills and frame are entry points of these flies from the outdoors.

Caulk them with a quality sealant to prevent these gnats and other irritating pests from invading your home through these gaps.

Installing meshed window screens on the windows and bug zappers at the outdoor area also prevent these flies from entering the homes.

Keep The Overripe Fruit Inside The Refrigerator

Overripe and rotten fruit inside the house attract fruit flies. Dispose of the rotting food, fruits, and vegetables, and keep the ripe fruits and veggies inside the refrigerator.

Use Pyrethrin-Based Sprays

Pyrethrin-based sprays kill these flies on contact.

Use these sprays where you’ve noticed flying insects, such as at the garbage disposal cans, underneath sinks, in the basement, and the bathroom.

However, ensure that you read the safety instructions and follow them. Also, do not use the outdoor sprays indoors and indoor sprays outdoors.

As a repellent, you can use peppermint oil spray in your kitchen, bathroom, and on the windows to keep these flies away.

Final Words

The small black flying bugs in the house that are not fruit flies are fungus gnats, phorid flies, and drain flies.

Inside the house these little black flies are typically found in moist environments such as kitchens and bathrooms.

But they can spread to the other areas of the house, following you, when the infestation worsens.

They can be active year round if you live in warm weather and don’t eliminate the conditions that sustain them.

Removing their breeding grounds and eliminating their sources, such as moisture, decaying organic matter, and food wastes, from your home and outdoors eliminate these flies.

1 thought on “3 Small Black Flying Bugs In The House, Not Fruit Flies”

  1. Thanks for this article. I have these fruit flies look alikes and wondering what they are. On observing closely I found out they are fungus gnats and phorid flies!

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