ANTS

This morning I came down to find ants in the kitchen. After spraying 409, wiping down the kitchen, killing and cleaning, I think I've located that they are coming in behind the fridge, which is odd seeing that it's not along the outside wall of the kitchen.
We spent most of the morning doing that, then looking for a "prego safe" chemical to prevent them from coming back. Boric acid is what Cilla suggested. Needless to say we did not attend church today.
What brought them in I am not quite sure.The past few days have acutally been warmer, so I dont' think it's the cold that brought them in. The dishes in the sink were dirty, but rinsed off.
Since this morning I've seen more, and added more of the boric acid to the cracks along the kitchen walls, yet I'm not convinced I've seen the last of them.
Like I have time to deal with ants with two more crazy weeks of school before Christmas and still have not a solid idea of what to get anyone for Christmas!?!