How to Get Rid of Drain Flies in the Bathroom?

Drain flies are household pests that are found near sources of water. They are commonly found near bathtubs and sinks in the kitchen and bathroom.

Drain flies are not known to transmit diseases to humans but some people may suffer from bronchial asthma due to the bite of the fly. The larvae of the drain fly can also get inside human tissue resulting in a patristic infection known as myiasis.

In this blog post, you will learn about the drain flies, including their appearance, feeding, and breeding patterns. You will also know what causes a drain fly infestation and how to get rid of drain flies in the bathroom.

Drain Flies: How to Identify Them?

Drain flies are usually black or brown in color. Upon closer inspection, you will find that they are dark at the ends and pale in the middle.

Also known as sewage flies, the female drain flies lay eggs on organic matter in greasy drain pipes. These are commonly found inside drain pipes in the bathroom, kitchen, storm drains, septic tanks, and moist compost.

Drain flies eat decomposing matter in the pipes. The flies feed on fungi, bacteria, and other microbial organisms inside the drains. These flies also resort to eating each other if the food runs out.

Causes of a Drain Fly Infestation

Understanding the reasons for drain file infestation is important to get rid of the pest infestation.

Dirty Drains

Drain flies lay eggs in dirty drains in the bathroom. They can also make a home in sewers outside the house. They can enter the bathroom from dirty exterior drains.

Female flies lay anywhere between 50 and 100 eggs. If the drain is not cleaned, it can result in hundreds of drain flies roaming inside the home or office.


Drain flies are common in bathrooms with groundwater. They are less likely to appear in homes with tap water. The reason is that tap water is treated with chemicals that inhibit the growth of flies.

But there is no guarantee that drain flies won’t appear in bathrooms with tap water since other factors also promote the growth of drain flies.

Moist Environment

Drain flies thrive in wet bathroom conditions. The insects prefer a moist environment. Bathroom floors that are mostly wet are a perfect breeding ground for the flies.

Damaged Bathroom Tiles

Flies will lay eggs between the cracks in tiles. It is important to repair broken tiles. Moreover, it is important to fill the space between tiles with grout to prevent drain fly infestation.

How to Get Rid of the Drain Flies from Bathroom?

Here are ways you can get rid of drain flies in your bathroom:

Cleaning the Drain

Drain flies feed on hair, crumbs, and soap scum in the drain. The non-liquid substances can also cause water to flow slowly down the drain. To prevent drain fly infestation, you should keep the drains keep at all times.

You should clean the drains both inside and outside the house. Here are some tips for cleaning the drain pipes to prevent drain fly infestation in the bathroom.

Warm Water Method

Drain flies are attracted to slime and grease that is present in drains. You should clean the drain by pouring warm water.

This will loosen the sludge inside the drain. You can then use a metal pipe to brush and clean waste from the drain using an up and down motion.

Cleaning Gel Method

You can also use a drainage cleaning gel to clean the drain. The cleaning gel coats the sides of the drainage pipe and removes organic matter. You should leave the gel for a few hours and then flush it clean with water in order to clean it.

Baking Soda Method

Another method to clean the drain to prevent drain fly infestation is to use a baking soda, vinegar, and salt solution. This method will effectively remove clogs and clean the drain.


  • Baking soda (1/2 cup)
  • White vinegar (1/4 cup)
  • Salt (1/2 cup)

Pour baking soda directly into the drain, and then pour white vinegar. Next, you should pour salt on top of baking soda and vinegar solution.

Leave the solution for about half an hour and then pour boiling water inside the drain. Make sure that you wear a glove to protect your hand when pouring boiling water down the drain.

Dish Liquid and Bleach Method

Using dish liquid and bleach can also clean the drain to get rid of drain fly infestation in the bathroom. This method is recommended to clean grease that had built up inside the drain.


  • Dish liquid (1 tablespoon)
  • Bleach (1 tablespoon)

You should pour the dish liquid directly down the drain. Next, you should add bleach into the drain. Leave the chemicals inside the drain for about two hours. Pour boiling water into the drain to dissolve and wash away the grease and slime inside the drain.

Enzyme Drain Cleaning Products

Enzyme draining cleaning products are recommended for cleaning a drain that is heavily clogged with hair or slime. You can use Biokleen Drain Gel and Earth Enzymes Dain Opener to clean a dirty drain in the bathroom.

Enzyme cleaning products contain eco-friendly enzymes bacteria that don’t cause any environmental damage.

These eat the organic matter inside the drain removing the clog. Some enzyme cleaners, such as the Green Gobbler Drain Clog Remover, contain a non-toxic acid monosodium sulfate that is effective in cleaning a heavily clogged drain.

Using a Drain Trap

Once you have cleaned the drain, you should use a drain trap to collect hair and other substances. The drain trap will collect hair and other substances preventing them from flowing down the drain.

Using the drain trap in the bathroom will eliminate the food sources of drain flies.

Spraying with Chemicals

Spraying insecticide on the drain flies will also get rid of the pest issue in the bathroom. Chemical sprays can kill both adult flies and larvae inside the drains or cracks of tiles. You should spray insecticide to kill eggs, larvae, and adult drain flies.

Consider spraying the chemical every week to prevent drain fly infestation. You should spray the chemical before going to bed at night.

Close the windows and doors after spraying the chemical. The next morning you should leave the windows open for at least 15 minutes before using the loo.

You should read the label to ensure that the chemical spray is suitable for use indoors. Carefully follow the instructions when using the insecticide to get rid of drain flies in the bathroom.

Sealing Entry Points

Sealing entry points is important to prevent drain flies from entering the bathroom.

Find out gaps inside the restroom from where drain flies can get inside. You should look for holes and other possible entry points near the windows and doors.

Seal the gaps to prevent drain flies from getting inside the bathroom. It is important to seal the hole that leads to the drain.

Also, you should fill holes between the tiles that have eroded over time with grout or cement. Call an expert for sealing the gaps and holes inside the bathroom if you find it difficult to fill the hole yourself.

Keeping the Bathroom Clean and Dry

Keep the bathroom clean and dry at all times. This will prevent drain flies and other pests from infesting the bathroom.

When cleaning the bathroom, you should add carbolic acid in the cleaning liquid. This will crush the eggs of the flies in the floors and drains.

Consider scrubbing the walls and floors with fragrant carbolic acid. The smell of the acid will kill eggs and larvae in the tiles and drains.

Never Flush Paper Towels

Flushing paper towels down the drain also increase the chances of drain fly infestation.

It can also increase the chances of a clog. Always dispose of paper towels in the dustbin rather than flushing them down the toilet.

Apart from paper towels, you should never flush eggshells, coffee grounds, medications, household cleaning products, and fruit peels.

These can clog the drain pipes and attract drain flies. The products don’t easily break down, resulting in a drain clog that will be costly to resolve.

Frequently Asked Questions

What is the most effective way to eliminate drain flies?

The most effective way to eliminate drain flies is to keep your bathroom and drain pipes clean.

Regularly cleaning your sink and bathtub, as well as pouring boiling water down the drain can help eliminate any breeding grounds for these pests. In some cases, using a drain gel specifically designed to break down organic matter may be necessary to remove larvae and eggs.

Are there any natural remedies for dealing with drain flies?

Yes, there are natural remedies for dealing with drain flies. You can try pouring a mixture of equal parts white vinegar and baking soda down your drain.

This combination will create a foam that helps break down and remove organic materials stuck in your pipes, which drain flies rely on for breeding. Another option is using essential oils like lavender, eucalyptus, or tea tree oil to deter drain flies from infesting your bathroom.

Can I use bleach to get rid of drain flies?

Although bleach can kill drain flies, it is not as effective in eliminating their larvae and eggs, making it a less efficient solution.

Using a drain gel specifically designed for dealing with drain flies or natural remedies, such as vinegar and baking soda, is a more effective approach.

Why are there drain flies in my bathroom?

Drain flies are attracted to your bathroom because they feed on and breed in the organic matter found in drain pipes.

This includes hair, soap scum, and other debris that may accumulate in damp and dark areas, such as bathroom drains and sinks.

What other pests may resemble drain flies?

Fungus gnats and fruit flies are two common pests that may resemble drain flies. Although they share similar physical characteristics, they breed in different environments.

Fungus gnats are attracted to damp soil in potted plants, while fruit flies are more commonly found near rotting fruits and vegetables.

How can I prevent future drain fly infestations?

To prevent future drain fly infestations, keep your bathroom surroundings clean and dry. Regularly inspect and clean drain pipes, removing any organic material that may accumulate.

Pouring boiling water down the drains can help loosen and remove any potential breeding grounds. Additionally, using a drain cover or screen can prevent debris from entering your pipes and reduce the chances of a drain fly infestation.

Final Remarks | Getting Rid of Drain Flies in Bathroom

Drain flies are not a carrier of diseases similar to cockroaches. Nevertheless, they can trigger asthma in some people. You can avoid drain fly infestation by cleaning the bathroom and sealing the holes.

Consider cleaning the drain once a week to prevent drain flies infestation in the bathroom. Clean the drains by pouring boiling water and chemical solutions mentioned in this article.

When cleaning the drains, you should always use chemicals that are safe for the environment. Avoid using cleaning products that contain harsh chemicals that are harmful if released in the sewage water.

Make sure that you wear protective gloves when using chemicals to clean the drain. Also, keep the windows and doors open for about half an hour before using the restroom.

This is important to avoid any health issues due to the fumes of the cleaning product.

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