If you're a mom with a green thumb or have kids and pets playing in the yard, an invasion by a black ant colony is the last thing you want to deal with. Although ant tunnels can promote aeration and moisture penetration in soil, ants protect garden pests, such as scales and aphids, so they can feed on their honeydew. Regardless of which black ant species you're dealing with, they all belong to the insect order Hymenoptera. To get rid of them, you have to go to the source of the problem -- the nest.
Place commercial black ant bait in the yard near the ant nest and on nearby ant trails where the small pests roam. Ant bait can be purchased in a prepackaged solid, liquid or gel form. It contains one or more attractants, such as carbohydrates or protein, and a toxicant, such as boric acid. When the worker ants encounter the bait, they'll take small quantities back to the nest to share, which results in the death of the queen and the colony.
Put on gloves, safety goggles and a surgical-style face mask. Mix 1/4 cup of granulated sugar with 1/4 cup of boric acid in a bowl or mix 1 part boric acid with 9 parts corn syrup. Poke four small holes in the sides and lids of clean, empty margarine tubs. Put 1 tablespoon of the boric acid/sugar mixture, and three pieces of dry cat or dog kibble in each tub, or put a quarter-size dollop of the boric acid/corn syrup mixture in them. Label the containers and place them around the nest in areas the ants roam.
Run a rake vigorously over the ant hill to completely destroy it. Alternatively, bring a pot of water to a boil, and pour the hot water directly in the nest opening. You might have to repeat this method several times to get rid of the entire colony.
Slice up two to four hot peppers, and place them in a glass jar. Pour 1 quart of hot water into the jar, and place the lid on it. Let the peppers steep in the liquid for at least 24 hours. Then, take out the peppers and pour the liquid into the nest. The nest will become unlivable, and the ants will die.