Most of coastal California is one big Argentine ant colony by now. We get lots of 'em. Finding the cracks they're coming in through and blowing in Cinnamon (using a straw) seems to keep the buggers out for a while, and leaves the house smelling nice. The only hard-core product we've found to work are the outdoor Grant's Ant Stakes. The fine print says to put a few drops of water in to activate the stake.

Good luck.