How to Get Rid of Gnats in Bathroom Drains & Sinks

The tinny insects flying all over your bathroom, under the sinks, in potted shower plants and in the drain are probably gnats. While they won’t destroy your bathroom fixtures, they’re generally a nuisance and some species can bite through your skin, resulting in the transmission of pathogens and diseases. Addressing an infestation on time is key, since gnats breed all the time.

Some of the best ways to get rid of gnats in your bathroom is to use traps, insecticides and DIY home remedies such as bleach or baking soda. There are also many other products in the market that can effectively eliminate gnats.

Read on to find out what exactly gnats are and the types you are likely to find your bathroom, causes or attractants, the various methods you can use to get rid of them as well as prevention measures to ensure they do not return.

What are Gnats?

Gnats are tiny black or dark-brown winged insects with long, slender bodies and they often fly in large numbers, called clouds. While many people confuse gnats for small baby flies, they’re full-grown adult insects.

The term gnat does not refer to a specific type of insect; it is rather a common name for any of the tiny flies. Gnats can be both biting and non-biting.

Types of Gnats that commonly get into the Bathroom

There are three types of Gnats that are commonly found in the bathroom. These are:

Fungus Gnats

These are tiny black flying insects that habituate moist areas that have rotting plant materials and also mold. These types of gnats are dark and have long legs around 2.5 mm in size. 

Fungus Gnat
Fungus Gnat

These gnats love to infest water-damaged cupboards and unhygienic drains where organic material collects. Since they are garbage feeders, they can spread bacteria

Fruit Flies

These are small brown flies that have large red googly red eyes. They love feeding on rotten fruits and vegetables and often make their way into the bathroom, mainly because they are attracted to water and damp places and the bathroom is one of the places.

Fruit Fly
Fruit fly

Further reading: Dealing with Fruit Flies in the Bathroom

Phorid or Humpbacked Flies

These are tiny but bulky flies that have bulging torsos. They are similar to fruit flies in appearance in that they are brown but do not have distinctive red eyes like fruit flies.

They have black eyes and they walk in zig-zag motion

Phorid Gnat
Humpbacked fly

 Where Gnats Hide in the Bathroom

In bathrooms, gnats swarm around damp areas like drains and showers, leaking pipes or rotting cupboards, and bathroom plants.

They can also be found around air conditioner vents.

Some can be found deep in exposed or leaking pipes that are the phorid gnats.

Dampness and moisture along with organic material in the drainpipe create the perfect breeding ground for gnats and this is one place they can be found. In the drain pipe.

Gnats can also be found on the plants in the bathroom since they are attracted to moist soil.

Causes of Gnats in Bathroom

Gnats are small enough to creep into just about anywhere and stay there. They can fit through the tiniest of cracks in doors and windows. There is always something in the bathroom that attracts a certain type of gnat.

Dampness and moisture and also dirt and garbage attract fungus gnats. If you leave dirt all over your house and a lot of trash in the kitchen, then this might be the cause of gnats in your bathroom.

Damp and moist environments attract fruit flies but also scents since they love rotten fruits they are also attracted to scents.

Maybe you left your glass of wine in the bathroom or spilled some wine and forgot to wash it off, this smell attracts them. Or maybe you were eating an orange as to were taking a bath in the bathtub and forgot the orange peels on the floor, then the scent may attract them.

Dampness and mainly the deep plumbing system also attract phorid flies, but leaking or exposed pipes and faucets mainly attract them.

How to get Rid of Gnats in the Bathroom

Gnats can be a nuisance in the bathroom since they fly and the buzz can be very irritating. They can also be a health hazard and for these reasons, you should do away with them before they get out of control.

There are several ways of getting rid of gnats in your bathroom. They include the following:

DIY Gnat Traps

Gnat traps are wonderful when it comes to getting rid of gnats in the bathroom. Following some ideas on to set up the traps

Vinegar Trap

The most popular gnats trap is a vinegar trap, which is simple and cost-effective to create.

To make this trap follow the following steps:

  1. Place a few tablespoons of apple – cider vinegar in a bowl
  2. Add a few drops of dish soap
  3. Add a tablespoon of sugar to the bowl
  4. Stir the mixture gently.
  5. Set your bowl in an area where gnats are prevalent, in your bathroom like near the bathtub or even the sink.

The sugar and apple-cider vinegar combination attracts the gnats, and the dish soap traps the gnats and eventually causes them to drown.

If you cannot access apple-cider vinegar presently, you can use a combination of red wine and dish soap can create a similar gnat trap. If your gnat infestation is particularly intense, you may want to set out a few bowls of this wine trap mixture around the house.

Yellow Food Coloring Traps

This method works best on fungal gnats since they are attracted to yellow. To make the trap, do the following:

  1. Mix some apple cider vinegar with a few drops of dishwashing detergent and yellow food coloring in a cup.
  2. Place a layer of cling film across the top of your container, keeping it in place with an elastic band.
  3. Make a few small holes in the film.

The yellow coloring and the acidic scent of the apple cider vinegar which mimics rotting vegetation attract the gnats, and then they get trapped inside the container.

Fruit Trap

This method is very effective for fruit flies.

Simply cover a jar of overripe fruit with plastic wrap and poke small holes into the wrap’s surface. The gnats may smell a food source and enter the jar, ending trapped.

There is also another way to make a fruit trap. Follow the steps below.

  1. Place some fruit skins in a disposable container, or you can also use a few tablespoons of beer or wine to attract the fruit flies.
  2. Wrap the container with a cling film layer, sealing it with an elastic band.
  3. Poke a few small access holes and then set it up in your bathroom.

If you do not have a beer, you can add a few teaspoons of sugar, yeast, and water, as this may mimic the fermentation process that attracts fruit flies.

Use Potato Chunks

Potatoes are very attractive to fungus gnat larvae, making this a good method of getting rid of gnats.

This method is well suited for someone who has potted plants or indoor plants in the bathroom.

For this method, follow the following steps:

Place raw potato chunks in the soil around the earthen pots. This trick will trap the larvae away from plant roots, as they are attracted to the potato.

After a few days in a pot, you can remove infested potato chunks and throw them into a basin of hot water to kill the gnats and replace them with fresh pieces.

Use Sticky Traps

Another way to get rid of gnats is by using sticky traps.

You can purchase the sticky traps available at retail nurseries and garden centers.

To set up these traps follow the steps below:

  1. Cut the yellow sticky traps into smaller squares
  2. Stick the small squares over the areas infested by the gnats such as the bathtub, sinks, and drains.
  3. The gnats sit over them and get stuck.

Make a Candle Trap

Light also attracts fly gnats just like other insects, and hence a candle trap can be used to get rid of them.

Place a candle in a candlestick and fill the holder partially with water.

Light the candle and turn off the lights.

The gnats flock to the flame and are burnt or may fall into the water and drown. 

When using this method, it is advisable to make sure you put out the candle flame before going to bed to prevent a fire outbreak.

Using a Gnat Spray

You can make a homemade gnat repellent spray. To make this spray follow the procedure

 make a mixture of dish soap, water baking soda and vinegar

The mixture should contain a few drops of dish soap, a tablespoon of vinegar, and baking soda per cup of water.

Fill it into a spray bottle.

Use this to spray on the gnats. A few sprays of this mixture are an effective gnat repellent. They may be sprayed in areas where gnats are common in the bathroom, such as the sink.

Bleach Your Drains

You can get rid of gnats around your bathroom sink or bathtub or even the drain by pouring a cup of diluted bleach down the drain to kill the gnats. Ensure you pour the bleach down the drain slowly until there are no more gnats.

Use Baking Soda and Vinegar Solution

You can also use baking soda and vinegar to kill gnats in the bathroom.

Pour baking soda down the bathroom sink and then add vinegar. The mixture fizzes and bubbles may come out of the drain pipe.

Let the mixture remain in the drain for one hour. Next, you should pour boiling water down to kill the gnats once and for all.

A baking soda and vinegar solution instantly kills the gnats, including eggs and larvae.

It may also loosen the organic material inside the drain pipes that gets rid of the food source of the flies.

Use Finger Nail Polish

The chemical acetone which is found in nail polish can effectively kill gnats, and hence you can use nail polish or nailed polish remover to get rid of gnats in your bathroom.


  1. Take a see-through glass
  2. Stick some cotton in it using glue
  3. Put some nail polish remover on the cloth and cover it over the drain.

The nail polish remover attracts the gnats when they come out of the drain, and once they get in contact with the cotton they may sit on it, and they shall die instantly.

Use Baking Soda Paste

Baking soda solution does not just kill the gnats but can also clean the pipes and drains.

For this method, follow the steps below:

  1. Put half a cup of baking soda in a bowl.
  2. Add one cup of water to the bowl.
  3. Mix the baking soda until you get a paste consistency.
  4. Then coat the surface of the tiles and bathtub with the paste. Make sure that you wear gloves when applying the paste.
  5. Let the mixture sit there until it turns dry. It may take about six minutes for the baking soda to dry.
  6. Turn on the water and use a rubbing brush to wash the tile and bathtub.
  7. Clean the area thoroughly to remove gnat eggs on the tile and bathtub surface.

Use Ammonia Solution

Using ammonia is also an effective to curb gnats in your bathroom. The following are the steps

  1. Add about 3 cups (ca. 710 cubic centimeters) of ammonia in a gallon of steaming hot water to create a mixture for killing gnats in the bathroom.
  2. Use this liquid mixture to clean the drain and bathtub and any other area infested by the gnats.
  3. Leave the liquid for about five minutes and then flush or wash it clean
  4. You can also use a scrubber to apply ammonia solution at the base of the toilet.
  5. Next, you should add boiling water to kill the gnat eggs.
  6. Make sure that you wait about 3 minutes before pouring the hot water around the toilet base.
  7.  Lastly, you should wipe the area using a dry cloth to remove dampness.

Gnats that come into contact with ammonia cannot be able to mate. This effectively gets rid of gnat infestation from the bathroom.

Note that

When using this method, you need to open the doors and windows of the bathroom, as the fumes of the mixture can be toxic.

Be sure to cover your eyes and ears when pouring ammonia into the water.

Use BTI or Gnatrol

BTI is a naturally occurring fungus found in the soil that is toxic to gnat larvae. It contains spores that produce toxins that target and specifically harm the larvae of mosquitoes, blackfly, and fungus gnat.

This can be applied over your potted plants repeatedly for gnat control.

It is non-toxic to humans and available in the nurseries.

Bathroom Gnats Prevention Tips

Prevention is more effective in keeping gnats out of the bathroom, and it’s better to prevent them as early as possible.

Here are some tips to prevent a gnat infestation in your bathroom.

Keep the Bathroom Clean

Always keep the areas around the shower, bathtub, and sink dry and free from any kind of dirt and filth.

To keep the bathroom clean, do the following:

Check the area near the bathtub and sink for stagnant water. If there is any, mop the water immediately to avoid giving gnat flies a chance to breed.

Keep the shower curtains dry and clean because gnats can lay their eggs on the curtains if they remain wet most of the day.

Clean the Drains

Dirty drains are one of the main reasons that gnats infest your bathroom.

Use baking soda and an ammonia solution to clean the drain pipes each week.

You can also use a metal pipe brush to clean the drains. Push the metal pipe into the drain and move the brush back and forth to remove gunk build-up inside the pipes. Once you have cleaned the drain, you should pour boiling water down the pipe. This water flushes the organic material down the drain. Since the organic material is the food source, and it’s gone, this prevents gnats infestation.

Avoid excess watering of potted plants in the bathroom

Moist soil attracts gnats, hence excess watering of the plants in the bathroom can attract them.

Fix Leaky Pipes

Leaks create a puddle of water that creates an ideal breeding spot for gnats and when they are fixed this prevents the breeding.

Check the pipes regularly for a leak in case there’s any ensure it is fixed instantly.

Store Towels in Lidded Hamper

Gnat flies can lay eggs in wet towels. You must store towels in a lidded hamper to prevent female gnats from laying eggs.

In addition, you should keep the curtains and blinds open to let sunlight inside. Sunlight can dry wet towels, thereby preventing a gnat infestation.

More on Insects, Bugs & Pests in the Bathroom



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