Bifenthrin(Talstar, Upstar, Brigade) is great for ants. It's one of the only chemicals that is allowed for use on plants shipped out of the fire ant quarantine zone. It comes as a granular product as well as in a liquid formulation. It is fast, persistent at higher rates, relatively safe for humans, and fairly inexpensive in the ag labeled form. Another product that I've also used is diazinon. It works for mound treatments, but is a little more toxic to humans than bifenthrin.