I wonder what the queen looks like. Here's what to do: Mix sugar with borax in a water solution. Soak a cotton ball in it and drop the cotton ball close to their food source. They'll take it back to their queen 95% of the time. The other 5%? Some ants are protein driven (instead of sugar), so just observe what they're after and use that. Also, never use ant spray. They sense danger and'll start having more queens and create more colonies (and more work to kill them all around your house.) Keep trees and bushes away from touching your house.