TERRO Outdoor Ant Killer Spray Kills ants, carpenter ants, spiders, cockroaches & other insects. An easy-to-use, precision spray tube allows you to deliver barrier spray in hard-to-reach places up to 10-15 feet away. When sprayed, the outdoor ant killer expands upon hitting the surface and leaves an invisible residual deposit. TERRO Outdoor Ant Killer is ideal as a perimeter barrier around foundations, doors and windows. It is especially useful outside in early spring when ants emerge and attempt to enter the house. Use again in the fall when ants attempt to come inside for the winter.