Originally Posted by lorax

Aspartame will kill them; so will a 50-50 mix of borax and white sugar (my fave, they get all drunk and then take it back to the queen and kill her with it.)

DE is great too, but it's a deterrent, not a cure. And for anthills in the yard, I absolutely love the old standby of soaking your rubber boots in kerosene, stirring baking soda into the hill, and then dousing it with vinegar - you get a foamy volcano of ant death!