The problem with sprays is that they may only kill a few workers and no not destroy a colony that is well hidden. However, sprays do work quickly. Do not use sprays with baits, because you want the workers to carry the poison bait back to the nest. If they are killed on the way by the spray, they cannot feed the poison to the rest of the colony. If you can trace the ants to a nest in the yard, finely grind up orange peels in the blender or food processor and pour immediately in to the entrance holes.
Citrus peels contain oils useful for controlling ants.
This method works best on hot summer days. Granules and other types of insecticides may also be used outdoors to control ants. Ants often disappear from your house as suddenly and mysteriously as they appeared. Usually this means they have found a better source outside or that the adverse weather conditions have dissipated. The University of Arizona , College of Agriculture , Cooperative Extension , in Maricopa County .