How to Get Rid of Drain Flies | Roto-Rooter
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How to Get Rid of Drain Flies

Drain flies

Few things are more annoying than fruit, sewer and drain flies invading your kitchen or bathroom. The pesky insects thrive on rotting foods and other organic matter found inside moist drains. Drain and fruit flies are harmless though they can carry bacteria from rotting foods that can contaminate other foods. There are many ways to resolve this issue – so put down the fly swatter and learn about some of the fastest ways to rid yourself of drain flies and get your drain back to normal!

How Do You Know If You Have Drain Flies?

Determining whether you have drain flies, sewer flies or fruit flies is easy. These insects are typically spotted on walls and ceilings near the areas you may suspect them, which in this case, is your sink.

Alternative Method for Determining If You Have Drain Flies

Another easy way to determine if you have sewer flies is to apply a piece of tape over the top of your drain and leave it for at least two days. After 48 hours, return to the suspected sink and see if there are any drain flies stuck to the tape. Drain flies have a life cycle of up to three weeks and they lay eggs every 2 days. Covering your drain with tape over this period will ensure you are seeing the entire population of sewer flies within your sink.

Tools & Supplies


  • Measuring Cup
  • Pipe Brush
  • Plastic Wrap


  • Salt
  • Baking Soda
  • Vinegar (White or Apple Cider)
  • Water
  • Bleach
  • Dish Soap
  • Ripe Fruit
  • Tape

Step 1: Sanitize & Clean your Drain

While some insecticides and household chemicals can be used as a drain fly killer, there are also many natural ways to take care of things. These drain fly killer solutions can get the job done, but going the natural route is better for you and your home. First things first, you'll want to clean out the drain in question. There are a few ways to do this:

  1. Pour a 1/2 cup of salt, 1/2 cup of baking soda and 1 cup of vinegar and allow it to work its magic overnight. Follow up with boiling water the next morning. Repeat if necessary.
  2. Pour a half gallon of water and 1 cup of vinegar or bleach down the drain to sanitize.
  3. Pour boiling water down the drain to loosen rotting matter. Use a metal pipe brush to clean the pipe lining. Follow with more boiling water.

Step 2: Create a Homemade Trap

After sanitizing the drain, you may want to create a homemade trap to catch the remaining flies.

  1. Place a small piece of ripe fruit in a cup covered with plastic wrap. Next, make small puncture marks in the wrap with a fork. This method is perfect for catching fruit flies.
  2. Mix a cup and a half of apple cider vinegar and 5 drops of dish soap and place near the drain (heat in the microwave for 15 seconds to attract more flies).

What You Should Do If Drain Flies Come Back

If these methods do not work to kill drain flies, you may have an issue with your p-trap. Every kitchen or bathroom drain has a self-sealing water trap, which stores about two cups of water in a U-shaped bend that sits below the piping and the fixture. When there is no water in the pipe due to cracks or non-use, odors and sewer flies can escape. If the drain flies come back, there may be something wrong with your p-trap or a drain line. Schedule a Roto-Rooter service here and we'll help you clean your drain and get your kitchen back to normal in no time.