If you have a fruit fly infestation in your kitchen, like the one we've been having for the last several days, here's a way to get rid of them without insecticides.
Get a small plastic container, put some pieces of partially rotten fruit in it and then leave it with the lid off on a counter top where the fruit flies are loitering. Now leave the room for a while, say, 20 minutes. When you return, there will be a bunch of them Drosophila in the container. Pick up the lid and bring it very slowly to the container—the fruit flies seem to have good eye sight and/or are very sensitive to any movements around them—and when the lid is just about over the opening, bring it down quickly to seal the container. Take the container outside, open the lid and release the prisoners, then bring the container back in and repeat the process until the numbers of the flies come down to a tolerable level (you can't eliminate them all).
Here is my Drosophila Motel (patent pending, of course!) named after the famous Roach Motel. The suckers inside will soon be deported. The red-stained paper was from a raspberry box.
Yes, you may have to repeat the process several times, but, hey, would you rather spray your kitchen with an insecticide?