Gnats/flies around bathroom window and coming out of drain - Ask Extension
I suspected small flies were coming out of my second floor shower drain, so taped over it and had my suspicions confirmed. After showering and pouring...
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Gnats/flies around bathroom window and coming out of drain #729435
Asked October 08, 2020, 12:49 AM EDT
I suspected small flies were coming out of my second floor shower drain, so taped over it and had my suspicions confirmed. After showering and pouring an enzyme drain cleaner down the drain, I noticed two more on the shower wall. I inspected the window that is inside the shower, and discovered maybe half a dozen of these small flies were between the screen and window.
My suspicion is maybe they came in while the window is open and found their way into the drain? But there was definitely at least one that came up through the drain and was flying underneath the tape I laid over the drain.
I attached photos of the ones found inside the window, between the screen and glass. I apologize for the quality, but these were the best I could get with the lighting as it was. Is it possible to tell what these insects might be and how to resolve the issue?
New York County New York
Expert Response
Hello,
Thanks for your question. From the images, I can only guess what you're dealing with and my best guess is maybe fungus gnats like this: https://bugguide.net/node/view/1491615
They breed in wet areas, wet soil, even water-soaked wood. There are two possibilities here, as you've kind of indicated. Either they came in from outside (and were attracted to the drain, went inside the drain) or they are coming from inside the drain. For any drain fly, and there are flies that specialize in drain goo, we always recommend the enzymatic cleansers made for drains. So you've use an enzyme cleanser and you might try one more time just to be sure. My suspicion, though, is that these flies are coming inside from elsewhere. I do not know what your surroundings are like, so I can't make good recommendations, but things to look for are overwatered potted plants, overly irrigated landscape areas, water leaks from outdoor spigots, roof or window leaks that result in wet indoor areas.
I am assuming that since your question is tagged with "New York County" you are in Manhattan or in NYC. In that case, roof leaks many floors up or pipe leaks from units above can cause wet areas, too. If the problem persists, it might be a good idea to have the insects identified to species and discussing with the bldg super. If you want to send me specimens to identify, I'm happy to do that. You can put them in dry tissue in a pill bottle or something sturdy and mail them to me at J. Gangloff-Kaufmann, NYSIPM, Cornell University, 60 Fire Island Ave, Babylon, NY 11702. If you mail specimens please let me know because we are not in the office most days.
I hope this helps!
Thanks for your question. From the images, I can only guess what you're dealing with and my best guess is maybe fungus gnats like this: https://bugguide.net/node/view/1491615
They breed in wet areas, wet soil, even water-soaked wood. There are two possibilities here, as you've kind of indicated. Either they came in from outside (and were attracted to the drain, went inside the drain) or they are coming from inside the drain. For any drain fly, and there are flies that specialize in drain goo, we always recommend the enzymatic cleansers made for drains. So you've use an enzyme cleanser and you might try one more time just to be sure. My suspicion, though, is that these flies are coming inside from elsewhere. I do not know what your surroundings are like, so I can't make good recommendations, but things to look for are overwatered potted plants, overly irrigated landscape areas, water leaks from outdoor spigots, roof or window leaks that result in wet indoor areas.
I am assuming that since your question is tagged with "New York County" you are in Manhattan or in NYC. In that case, roof leaks many floors up or pipe leaks from units above can cause wet areas, too. If the problem persists, it might be a good idea to have the insects identified to species and discussing with the bldg super. If you want to send me specimens to identify, I'm happy to do that. You can put them in dry tissue in a pill bottle or something sturdy and mail them to me at J. Gangloff-Kaufmann, NYSIPM, Cornell University, 60 Fire Island Ave, Babylon, NY 11702. If you mail specimens please let me know because we are not in the office most days.
I hope this helps!
