Do Gnats Gnarl or Merely Gnaw?

We have had gnats in the kitchen since early July. I think they hitchhiked in on a watermelon, and have stayed long past their welcome. Except for occasionally colliding with your face, they do not seem to being doing any specific harm, but I want them out! Tough to do in a kitchen. It's not like you can just use bug spray and nuke the little suckers. So tonight, I going to open the windows and the doors and use the leaf blower on them. They should be hitting downtwon St. Louis like meteors about midnight.