2

Since I moved into my house I started noticing drain flies coming into my bathroom and kitchen. Sometimes there are a lot of them, I once counted more than fifty. In my bathroom there is a septic put under the floor that collects the sewage water with a double lid that I had sealed off. I think they live over there. They are very annoying.

The flies keep reappearing, I guess from slits and holes that connect the bathroom to the area behind the walls and fake ceiling. Sometimes the flies are gone for a month, but they always return.
I know little of drain flies and I'm looking for a way to exterminate them, so they won't reappear ever. A second question is, how to identify where they breed?

Notes:
- I will try to completely seal the holes and slits in the the bathroom and kitchen (if that is possible)
- I dont have access to the septic put and I dont want to break open the walls
- I prefer no to use antyhing poisonuous
- there are no windows in the bathroom, but there is a ventilator in the ceiling, so the humidity is above average.

drain fly

  • 1
    Hi Slowspark, Welcome to Lifehacks.StackExchange. We hope you enjoy sharing knowledge and experience here. When was the last time the septic tank, vents, leech field, etc. was inspected or cleaned? Have you prior experience with septic tanks before you moved in there? – Stan Aug 1 at 23:01
  • @Stan Hi, the septic put is an old mortar and brick type. I did the renovation of the bathroom and kitchen myself, so all the drains are new, but there is an old drain from the demolished old bathroom upstairs that connects to the rain pipe and the septic put. There is no leach pit, it is connected with an overflow to the street sewage system. I prefer not to have any experience with a septic tank :) it wasn't cleaned during renovation, but the purpose is to keep it closed forever. I think it is a potential breeding ground for the drain flies. – Slowspark Aug 2 at 18:39
  • I ask because I've had to clean a couple and other related pleasant experiences. Sometimes they get filled with things that should go into land fill rather than … You know this. Is there any residual odour? Follow your nose. – Stan Aug 2 at 19:41
  • Hi Stan, my toilet is also connected to the septic tank, so its not only sink/shower water. There is sometimes odor of the septic tank, because I think it i not completely sealed-off air-tight in my bathroom, but I cannot point directly to the spot where it is not sealed. – Slowspark Aug 7 at 7:13
2

I'm a huge fan of fly strips (a.k.a. fly paper). The strips are cheap and low tech. And one strip can catch a lot of flies.

fly strips

I would hang them anywhere you see the flies, and anywhere you think the flies might be originating from. Replace the strips whenever there are too many flies on them (and they look gross).

Hopefully, within a few weeks you'll catch all the flies. That's happened in my home a few times: we had an infestation, hung up some fly strips, and caught all the flies. The reason that's happened more than once is not because the original colony came back, it's that we brought more flies in via fresh fruit like peaches or something.

  • Hi Brett, I bought these fly catchers and hung them up in the bathroom and kitchen and I will let you know the results – Slowspark Aug 7 at 7:10
  • It may take a few days, but I hope they work as well they've worked for me! It's weirdly satisfying to start seeing dead flies stuck on them. – BrettFromLA Aug 7 at 11:31
  • Unfortunately, this is not the solution for me. After six days I only caught 2 drain flies on each fly strip. They don't seem attracted to the strip or the vinegar. I spot around 20 new flies every day, and normally I whack them all until I don't see any more flies. Also the flies die naturally near the window. When I hung the strips I stopped whacking to see if the strips helped, but it didn't. So the strips will not eliminate the whole population and prevent new fly life cycles. What are your thoughts? – Slowspark Aug 12 at 7:22
  • Sorry my suggestions didn't work on this type of flies! I'm currently dealing with fruit flies in my own home, and the fly strips and vinegar dishes are working for me. (Slowly.) To tag me directly in a comment, I think you can just put an "@" sign and then my name: @BrettFromLA. – BrettFromLA Aug 12 at 15:10
  • @Slowspark Sorry, I guess I don't know enough about that feature of the site! Maybe it doesn't work because I became a moderator recently...? – BrettFromLA Aug 13 at 13:03
2

It's possible that the flies are hatching from eggs laid in your pipes, rather than from entering your home. Here's a few things to try:

  1. Keep the drains clean and clog free.

  2. Make sure that there is no stagnant water in your bathroom or kitchen.

  3. Occasionally spray IGR (Insect Growth Regulator) in your drains. IGR spray prevents the drain fly eggs from breaking out of the larvae stage and hence can greatly reduce the chances of any future infestation.

https://www.fliesonly.com/how-to-get-rid-of-drain-flies/

  1. Use a metal pipe brush and push it through the pipe back and forth as far as it will allow followed by lots of boiling water.
  2. Trap flies by setting a bowl of equal parts sugar, water and white vinegar with a 5-10 drops of liquid dish soap on the counter next to the sink overnight. Flies will be attracted to the fragrant liquid and drown.
  3. Boil a pot of water and pour it down the drain 1-2 times daily for a week.
  4. Pour 1/2 cup of salt, 1/2 cup of baking soda and 1 cup of vinegar down the drain and allow to sit overnight. Follow with a pot of boiling water in the morning.
  5. Pour 1/4 cup of apple cider vinegar into a glass and cover tightly with plastic wrap. Poke holes in the plastic wrap with a fork and place the glass next to the sink. Flies will be attracted to the cider vinegar and work their way inside and drown.
  6. A natural product called Bio-Clean is a nontoxic, environmentally friendly drain cleaner that eats away at organic matter blocking your drain. Once the drain is cleaned, the flies will start to disappear.

https://www.mnn.com/your-home/at-home/stories/how-get-rid-drain-flies-naturally

0

I'm adding another answer because it's completely different than my first answer. I've used it in the past and it works surprisingly well!

1) Get a small bowl or dish.

2) Pour in some vinegar. It can be apple cider vinegar, white vinegar, or whatever you have available. I've used apple cider vinegar in the past. You only need about 1/4 cup.

3) Add a few drops of liquid dish soap. Stir it up just a little.

4) Do that several times, in several bowls.

5) Leave the bowls around your home where you've seen the flies. (Keep curious pets away from them!)

enter image description here

The flies will get attracted to the scent of the vinegar, and will attempt to drink it. The soap eliminates the surface tension of the vinegar, so the flies get sucked into the vinegar and sink to the bottom. You'll notice them in the bowls after a few hours or days.

  • ♦ see my comment on the fly strips, this also didn't work. I don't think the drain flies are like flies, they are more like moths and not interested in the sweet stuff. This is good for catching fruit flies though. – Slowspark Aug 12 at 7:24

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.