I live in Wisconsin, in a small 1BR second floor end unit/corner apartment in a 2-story building. Fall has been pretty warm this year so I have the windows open for at least part of the day (with screens). For over two months I've had a problem with tiny, slow-flying flies. Not fruit flies (not interested in vinegar, I've never seen them on fruit in the bowl). Apparently not drain flies, and they also do not look like fungus gnats. I get maybe a dozen of these per day in my apartment. They are fairly quick in flight and impossible to catch in the air, but once they land on a surface it's pretty easy for a slow-moving human to smush them.
The kitchen has a double sink with garbage disposal and a dishwasher. Bathroom has a basin and a tub. I never see flies in/around/near any drain. I use the disposal occasionally but run it nightly to keep it clear. There are no other drains in the apartment. The kitchen garbage can is covered and I empty the plastic bag liner every 1-2 days. I've never seen any flies in or near the garbage can.
I do have a few potted plants. I have never seen a fly on or even near any of the plants, and there's nothing crawling on any plant's soil. With the except of one plant on a new pebble tray, all the plants are allowed to dry between waterings. The pebbles are about three weeks old (and appear fly-free) but I have had the fly issue for at least two months.
Occasionally they will land on food, but food isn't a big draw – a piece of cheese attracts a fly, but not a dozen flies. Just one or two max.
The thing the flies try hardest to do is flying up my nose. They also try to fly up my partner's nose (he does not live here). They will find me any time there's light, but they are much more attracted to me than to the light, so if I sit down in a dim room and open my laptop, suddenly a fly appears and makes a break for my nose.
A biologist friend theorized that they could be phorid flies originating in someone else's apartment/a vacant unit. If that's not the answer, what is? And how do I deal with them? I just saw one zooming merrily through the living room and I may lose my mind.
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