It happens to everyone at some point. You (or someone you live with) has left a piece of produce laying around, or it has fallen behind the Keurig, etc. And now there are little bugs buzzing around your kitchen like Allied bombers over occupied Europe. What are they, and what can you do about them?
First of all, find what it is the little jerks are after. More often than not, they're going to town on moldy or rotten fruits or vegetables. So man up and go spelunking around the house for that gray, fuzzy little treasure. Once you find it, wrap it in a plastic bag and get it out of the house.
So you've destroyed what's attracting the hell-spawn flying around the house, but what are they? Most likely, they're Fruit Flies. The same little guys you were probably forced to do experiments on in science class (if you enjoyed a quality public-schooling edjumacatin' like me). So in short, they're little jerks, and you need a way to get them out. Here's what you do:
Pour a glass of red wine. Drink it.
Pour another. Drink it.
Pour another. Now leave it on the counter. And walk away. Just like Amy Winehouse never did.
Check back in a day, you will see all of your little Fruit Fly buddies (or most of them) floating in the wine. You see, Fruit Flies love wine. They're like Terminators, biologically engineered to seek the stuff out. Here's an article explaining how they do it: http://www.livescience.com/7256-fruit-flies-find-wine.html.
Now dump the mixture of carcasses and merlot out, and put a fresh glass out. Repeat until the flies are thinned out. But take heed. for Fruit Flys are much like the Sandpeople of Tattooine. Leave more bad produce out and they will be back. And in greater numbers.