Hey, I have been there! I really think ants are amazing creatures, but when they take over your life? Not cute. Years ago my mom stumbled across this stuff online...
OK Ant Killer. We had tried EVERYTHING to get rid of the buggers. Nothing worked... This stuff does. They don't really say what exactly it is, but it works by causing the ants to go crazy and kill each other. It ships from Malaysia in cute handmade envelopes. Tiny silver packets of what looks kinda like corn-meal... Maybe a teaspoon per packet? Anyway, you put it out and the next day... NO ANTS. It lasts for weeks, as it gets the whole colony. The $20 or so you spend will last about two years. At least it did in our case, and we had TONS of ants EVERYWHERE. They say it's non-toxic.

Like I said, the don't really tell you what it is, but in my experience it has never caused any harm to pets or kids or anything. It's worth a shot.

WAIT! They do tell you what it is!!! Sorry.

Tetramethrin 0.45%
Alphacypermethrin 0.02%