I was watching a gardening show on PBS and this guy said to use any type of powder borax, comet....etc... and put a thin line of it in the area that they are coming in from. I chose baby powder because I thought it would be least harmful if the kids saw it.
( by the way I had tried those little ant traps & they did nothing!)
It worked like a charm and they have not been back in over a month!
Appearantly the granuals of the powder feel like razor blades on the ants feet/body, if they walk on it-so they won't