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How To Get Rid of Drain Flies Once and For all

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Flies coming out of your drain are never pleasant.

Often times we think flies are getting in through open doors or windows.

This is not the case for drain flies. The flies enter your home from inside your pipes.

Unfortunately, identifying drain flies and getting rid of them is challenging.

Don’t worry; I’m here to help.

In this post, I am going to go over six ways you can get rid of drain flies.

Let’s get started.

What Do Drain Flies Look Like?

drain fly close up

Drain flies look like the combination of a moth and a fly. 

They have very similar characteristics as a fly but have furry wings and antennas. 

  • Size: Drain flies measure between 1.5 to 5 mm long. 
  • Legs: Flies have six legs. 
  • Wings and Antennae: They have two furry wings and two antennas with small hairs on them.
  • Behavior: Drain flies fold their wings over their body like a roof. 

What Causes Drain Flies?

There are several things that cause drain flies. 

These include

  • stagnant water in pipes 
  • Pipe build-up 
  • Sewer 
  • Soil with excess water 
  • Stagnant sewer water

Where Do Drain Flies Hide or Live?

Drain flies tend to target sewage water or stagnant bodies of water. 

Common areas that drain flies will hide include: 

  • Kitchen  and restroom sinks 
  • Sewers 
  • Drains 
  • Soil with excess water or sewage 
  • Outdoor drains 
  • Outdoor sinks 
  • Wet mops or buckets with stagnant water
  • Compost piles 
  • storm drains 
  • Excess moisture outdoors around structures. 

These are all common places where drain flies will hide or live around your home. 

How To Get Rid of Drain Flies

1. Identify Which Drains Have Flies

Before you begin treating drain flies, you want first to identify which drains are infested.

In most cases, you already know which rooms are experiencing drain flies.

Remember if there are flies in one drain, it’s possible for them to travel across pipes to other drains as well. 

You should inspect all the drains in your house to locate all the areas where drain flies are hiding. 

To determine whether there are flies inside your drain, you can place two tape strips across your drain.

Place these to make an “x” but so that it still allows ventilation through your drain.

Any flies that try to fly out will get stuck on the tap. This will help you identify if there are flies in the drain.

Another way you can inspect the inside of your drains is to use an endoscope.

At once, endoscopes were expensive, but not you can purchase a simple endoscope for less than $100.

2. Clean Your Drain

One step you can make to help you get rid of drain flies is to clean your drain.

Build-up around your drain is the primary reason for drain flies. Drain flies will feed on this build-up and also use it to lay their eggs. 

To eliminate drain flies, you need to remove this build-up to eliminate their food source and shelter. 

There are multiple ways you can clean your drain. 

  1. Natural Option
  2. Chemical Option 

Pro Tip: When cleaning your drain, you can do a few things to make sure the cleaning is as effective as possible.  

First, using a drain snake will help you remove any large object stuck inside your drain. 

You can also use a drain brush to help you remove any build-up found on the sides of your pipes. 

Natural Drain Cleaner

One common method you can use to clean your drain is to use the natural alternative. 

This commonly includes using common household items: vinegar, baking soda, and hot water. 

Below are the steps you need to take to clean your drain using common vinegar and baking soda. 

  1. Pour equal parts vinegar and baking soda into your drain. 
  2. After you pour them into your drain, cover your drain with a bowl or plate to trap the fumes inside.
  3. Wait 15 minutes before removing the cover. 
  4. After 15 minutes, pour 1 gallon of hot water down your drain. 
  5. Repeat this step multiple times until you are happy with your drain. 

Another natural option you can use is buying an all natrual drain enzyme. 

These enzymes are typically preferred because they are more effective at getting rid of large amounts of build-up.

Chemical Enzyme Cleaners

Chemical enzyme cleaners are a great way to clean your drains. These enzymes are specially designed to eliminate build-up found inside the drains.

The benefit of these cleaners is that they are strong but also safe to pour down drains.

This is important because many people think that they can use any strong chemical to clean their drain.

This is not the case; certain chemicals shouldn’t be poured down drains. In some states, it’s even illegal to pour certain chemicals down the drain.

3. Clean Out Your U-Trap

Another important area you want to clean is your U-traps.

U-traps or p-traps are designed to prevent fumes from the sewer systems from getting inside your home.

The issue is that the shape can cause build-up or debris to build up inside your trap.

Cleaning a u-trap is typically easy because you can remove the u-trap from your drain.

This will allow you to clean your u-trap and easily.

To easily clean your u-trap, you can use any cleaner such as bleach and a drain brush. This will make it easy to clean all the sides of the u-trap.

4. Use Drain Covers

Drains stoppers are typically used to prevent large items from going down your sink.

But, they are also an effective way of preventing drain flies from coming inside your home through the drain.

For this, I recommend using the mesh metal drain stopper.

Unlike plastic and rubber stoppers, metal stoppers wouldn’t easily tear.

And even the smallest hole can let drain flies inside your home, so it’s best to use metal.

5. Make sure your Water Traps are Full

Water traps are built into most plumbing systems for sink and shower drains. 

They prevent insects and vapors from the sewer from entering your home. 

However, sometimes, water traps dry up, rendering them ineffective at blocking drain flies from entering your home. 

Here are a few things you can do to make sure your drains traps are always full:

  • Install a trap primer at each water supply. Trap primers have sensors and automatically or timers that refill your water trap when it loses enough water.
  • If you have a drain that you rarely use, make sure to pour at least two cups of water into it at least once per month. Do this twice a month during the summer.
  • Pour a thin layer of mineral oil down your drain every couple of months. Doing so will prevent the water from evaporating fast.
  • Pour a trap seal primer down your drain. Trap seal primers are a biodegradable liquid that prevents your water trap from drying up. They typically last for three to six months or longer.
  • Flush your toilet regularly even if you are not using it to keep its water trap filled.

6. Check For Leaks And Damaged Pipes

Look around your home for any leaky pipes, broken drains, or broken pipes.

Drain flies will use any small cracks or leaks to get out of the drain and into your house.

Inspect the pipes around your home and look for any condensation or puddles of water.

If there are, you should contact a professional to have the damaged pipes repaired.

Depending on the severity of the damage, you can use purchase several items to fix cracked or damaged pipes.

What You Should Not Put Down Your Drain To Kill Drain Flies

1. Insecticides

While pouring insecticide down your drain may sound like a good idea, it’s not.

Insecticides have harmful chemicals that are illegal to pour down your drain in most states.

The drainage system in the U.S goes to water treatment centers, where water is recycled.

These water drainage systems can’t remove pesticides from water, and as a result, pesticides can go out to damage flowers, plants, and wildlife in the process.

2. Bleach

While bleach can kill cockroaches, pouring it down, your drain is not an ideal solution.

Pouring bleach down your drain is illegal in many states.

Bleach can react with calcium build-up and release fumes back up your drain.

It can also corrode pipes or cause them to burst.

3. Boiling Water

While pouring boiling water can kill  drain flies,  it’s not very useful.

By the time the boiling water reaches the drain flies, it will likely not be boiling anymore.

Plus, pouring an excessive amount of boiling water is dangerous.

The hot water breaks down the grease and fat in your pipes.

If you begin to melt the grease and fat, you will only provide more food to the roaches hiding deep in your pipes.

They will begin expecting food, and they will likely come searching for more in your pipes.

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