Ahem, the Borax solution is the best. Mix Borax with powdered sugar and leave it someplace where you often find ants loitering. The ants can't tell the leathal Borax from the powdered sugar and take it all back to the colonies crib. Then, everyone chows down and it's a scene fit for Jim Jones.
For the record, if you have loose soil, you could grow the equivalent of a 70's porn bush for a lawn or mow twice a day and the ants will still live more densely populated than Tokyo or that dirty city in India. They love loose soil.