A large part of my garden is in containers, so I am constantly battling ants that would like to take up residence. Here is how I get rid of them. When I find a pot crawling with ants, I sprinkle a little granular insecticide on the ground and a little on the surface of the soil in the pots, then water. Ants will vacate the premises in about 48 hours. I've also started sprinkling a little granular insecticide when I set out pots on the ground in the spring before the ants even have a chance to build a new home. It usually keeps the pots ant free for 2 months or so. This also works well for plants I keep in the greenhouse with saucers under them.