How do you kill Inch ants?

After my husband stepped in a nest we got serious. Used a product called "Ant Killer" by Garden Pro, sprinkled the granules all over the area. Next day there wasn't a single ant to be seen and the area has been clear ever since. The hardest part is finding the nest PAINLESSLY. Have had another sting today in a different area and have no idea where the nest is. Will try the borax in a jar method.