I spray around the outside of the house with Bayer Advanced Home pest and germ killer. I also spray it around the windows and doors. It is supposed to last up to 6 months and the bugs aren't supposed to cross the line. I also put small bowls of a mixture of powdered sugar and boric acid along my counters. My ants are finally gone.
We have had ants in our house since we built it 15 years ago. Since I started spraying once a year they are finally gone.