Black ants are often found inside the home. While they sometimes nest in the walls, black ants are often traced back to nests outdoors. Black ants build nests in the ground and other places outdoors, using underground tunnels to move back and forth between the colony's satellite nests. Although insecticides help eradicate black ants, successful extermination relies on killing the ants in the nest, too.
Spoon honey into empty, clean bottle caps from soda bottles or milk jugs. Set the honey-filled caps in and outside of the home where ants have been seen. Observe ants coming to and from the honey to help determine where the ant nests are stationed.
Apply diazinon liquid or powder to the ant nests in the ground. Purchase diazinon at the hardware store and follow package directions for proper application.
Mix 1/2 cup apple jelly and 1 tbsp. boric acid in a bowl. Spoon the ant bait into leftover bottle caps. Set the toxic ant bait indoors, inside cabinets or under appliances, and outdoors away from children and pets. Ants that are away from the nest eat the toxic bait and share it with any ants still living in the nests.
Check structures close to the ant nest, such as foundations or outdoor plumbing. Caulk any openings or gaps to prevent ants from getting into the house to build new nests.
Replenish ant bait and apply more diazinon as needed until the ant nests are completely destroyed. Ants travel back to the nest the day after applying ant-killing chemicals, so it's important to continue with extermination efforts until ants are no longer seen.