Infestation of tiny bugs

Asked August 25, 2015, 1:51 PM EDT

I live in a daylight basement apartment with a slab underneath. Lately I have noticed very tiny bugs flying around my living room. They are black and very small. I only have two windows in my apartment and I noticed yesterday, there is an infestation of these tiny creatures on my windowsill and gathered in the corners and the woodwork around the windows. I do have an air conditioner in one of those windows. I also have a hanging ivy plant in one of the windows. Last night I tried to gather as many of the bugs as I could in bacterial wipes and then sprayed with Home Defense. This morning there they were again as if I had never removed them. I am trying some traps but they don't seem interested. I do have window screens and very seldom open the windows so they must come through the screens and through cracks around the windows. On the outside of one of the windows are high rose bushes with a lot of rotting material on them. Could this be attracting these little monsters, and how can I prevent them from coming in? I really need to get rid of them for good!

Cumberland County Maine phorid flies drain flies

3 Responses

Hello, Thank you for your inquiry regarding the tiny bugs found in your home. The first step in permanently solving an issue such as yours is to get an accurate identification of the critters. You can do this by contacting your local Cooperative Extension office (Cumberland County Extension Office, UMaine Regional Learning Center, 75 Clearwater Drive, Suite 104, Falmouth, ME 04105, Phone: 207.781.6099 or 800.287.1471 (in Maine)), or the UMaine Extension Pest Management office (1-800-287-0279). If you can take a close-up focussed photo of the critter, ask either of those offices if you can send it to them by email so that they can identify it quickly. Otherwise, ask them how to package some samples so you can send it to them by mail. After the insects are properly identified, they will give you recommendations for managing it. I do not recommend that you apply any more pesticides, because as you found out, pesticides may not be effective in this situation. A common source of insects is firewood. Do you have firewood in your home? We generally recommend that you do not move firewood indoors until you need it, and then store only the amount you need for a given week. Some common insects and resources to help you manage them can be found on our website: I hope this helps you get started on finding a permanent solution for this issue. Sincerely,

Thank you for the reply. I have identified the critters; they are called phorid flies. They seem to get inside through one window that has screens and is never opened. I do not have a wood stove. Directly outside that window are high rose bushes with quite a lot of rotted debris on it. I did try some flying insect spray inside the apartment and on the outside of both windows, but they are still coming in. Do you know of anything else I can try?

Great! Now that you have identified the insect you are halfway to solving the problem! I think that the most likely source of these flies is in a drain in your home and that the reason you are finding them on the windows is that they are attracted to the light and would like to get out of your home, not into it! Phorid flies are commonly called 'drain flies' because they breed in the slimy stuff that can build up inside floor or sink drains, or garbage disposal units in sink drains or the food-filter traps in dishwashers. One way to isolate the source is to put some clear tape sticky side down, or a jar, over the drains. Leave in place for 24 hrs or at least overnight with the lights on, so that the flies are attracted to the light shining through the tape but get stuck on the tape. If you find these flies stuck to the tape covering a drain, you have found the source! You should clean all drains very thoroughly with a long handled brush (an old toothbrush works well for small sink drains). You'll need to remove the stopper mechanisms and/or covers (floor drain covers may be screwed down, in which case you need to unscrew the cover so that you can remove it). An enzyme based drain cleaner will help loosen the grime so that you can more effectively brush it out. a good fact sheet about drain flies is: