Mix 1 teaspoon boric acid with 1/2 cup honey.
Heat the mixture until the acid dissolves.
Mix 1/2 cup plus 1 tsp of water with the honey/acid mixture.
Fill the eyedropper with the water/honey/acid mixture. Leave some out for the ants for at least two weeks.
Second Solution -- For Carpenter Ants
Use the honey as bait. Place small dabs of diluted honey onto the back of the non-sticky side of some masking tape.
Allow the ants to feed on the honey. Follow them back to their nest
Use a power drill to drill a series of small holes (1/8 inch) into the places where the ants are entering and hiding. Drill and treat at least 3 to 6 feet on either side of a wall if you suspect a nest inside.
Puff boric acid into the ant's nesting areas. The boric acid will disperse and kill the ants.