There are simple remedies to get rid of those pesky fruit flies or gnats that flit around the kitchen in the summertime. They don't really hurt anything...they're simply annoying and ever-present.
Here's a simple remedy that I used this week.
Place a tablespoon of cider vinegar and about a 1/4 cup of water in a small glass or jar. Place plastic wrap over the jar. If you wish, you can secure it with a rubber band. Poke several holes in the plastic with a tooth pick. You want the holes to be large enough for gnats to crawl through. Once inside the jar they seem to be unable to find their way back out through those same holes. They're sorta klutzy that way.
I've read where others add a teaspoon of dish detergent to the vinegar. I suppose that tends to cause them to be unable to retreat from the vinegar but I did not do that. The jar I rinsed out this morning had two dozen of the critters - dead in the vinegar.