I had ants in my animal room, I tried the ant traps (little plastic squares) and they didn't work at all. I bought MaxAttrax Ultra ant killer and it got rid of all ants within a couple days. If they don't get stuck in it and die, they take it back and it kills all the others. It's a clear gel that you apply with a syringe-like thing. It's like deadly to animals though, so it would have to go where cats and such can't get to it (I have two cats but they don't go in the animal room). I don't know if it works for all ant species, but these were small black ones and it definately worked for me.
