Or use one of the gel type baits. They take the poison back to the nest and it will kill the entire nest. Spray a few workers and kill them where they are... others will continue to keep coming and the nest keeps growing. I've had good luck with those....every year or two I'd get a teeny little ant invasian...a few strateglically placed dollops of the gel at a few spots on the path they are moving along....leave them alone and the problem goes away very quickly and for a good while.