If they are actually fruit flies, you'll need to starve them out and trap them, the simplest way to make a trap is to just put some fruit juice in a cup, and stretch saran wrap tight over the cup. make sure that all the sides are sealed, then poke little holes in the top of the saran wrap, the flies are better at getting in than getting out. More importantly, you'll need to remove any and all food sources that they might be breeding in. Check bags of potatoes, onions etc in the pantry, put all your food away immediately, don't leave out wine, etc. I had a swarm of them invade my apartment this summer for the longest time until i found an old bag of potatoes in my cabinet that they had colonized, it was pretty awful.