Ants are beneficial insects, helping to clean up decaying organic matter and aerate the soil. Occasionally, however, they can become a nuisance. For example, ants often help to protect aphids, increasing the damage that aphids do in a garden. Other ants bite and may become an annoyance whenever you're trying to enjoy your outdoor landscape. If an ant hill is causing problems, several methods -- ranging from organic, nontoxic remedies to stronger, more toxic pesticides -- can you help you eradicate the ants and get rid of the hill.
Ants and Their Hills
Ants come in many sizes, ranging from 1/8 inch to more than 1/2 inch in length. The insects have a large front section and bottom section, connected by a tiny, thin midsection. This helps to differentiate them from termites, which have a more evenly shaped body.
Ants typically build their hills on bare, open soil. Sometimes, this patch of soil may be near a sheltering structure, such as the base of a garden shed or near a dead tree stump. As the ants dig their tunnels underground, they deposit the soil at the top of their burrow or close nearby, creating the tell-tale mound shape.
Boil the Hill to Death
For immediate and efficient organic control of an ant hill, fill a pot with approximately 3 gallons of water and bring it to a roiling boil. Wearing protective oven mitts, take the pot of water outside and pour the boiling water directly onto the ant hill. The water immediately collapses the hill's underground tunnels, and the hot water and resulting steam kills ants on contact.
Bucket the Hill
Bucketing requires more physical work than the boiling water method. When it's done right, however, it can remove an ant hill in a single day.
- Monitor the ant hill. Find what time of day the ants are least active and haven't yet left their nest to forage. In most cases this is the early to midmorning, since ant activity generally doesn't pick up until the sun has warmed the ground.
- Wear jeans or pants and closed-toe shoes. Tuck the bottom of the jeans or pants into the shoes and tie the shoes tight. This prevents ants from easily accessing your bare skin.
- Sprinkle a garden spade and the inside of a bucket with a generous coating of baby powder. The powder prevents any ants from climbing up the sides of the bucket or up the handle of the shovel.
- Dig out the ant hill using the garden spade. Remove all soil in a 12-inch radius around the hill and under the hill.
- Place the soil into the bucket.
- Add one or two squirts of dish detergent.
- Fill the bucket with water, then stir with a spatula or spoon to mix the soap, water and dirt.
- Set the bucket aside. The soapy mixture drowns and kills the ants after a few hours.
Try the Power of Citrus Oil
Citrus oil contains d-limonene, a plant extract that dissolves the exoskeletons in ants and other insects and quickly kills them. You can find it in many garden stores and hardware stores. Pour 1 1/2 ounces of citrus oil, such as orange oil, into a bucket. Add 3 ounces of liquid dish detergent plus a gallon of tap water. Mix, then pour the solution onto the ant hill. As the liquid moves down through the dirt, it collapses ant tunnels and kills ants on contact.
Make a Homemade Insecticide Bait
Some ants like sugar. Other ants like fat and protein. Dab honey or fruit jam onto a postcard or piece of cardboard. On another piece of cardboard, smear some peanut butter. Place the two cards of bait near the ant hill and inspect the bait after a few hours. Whichever card has the most ants will pinpoint just what kind of ant bait works best in your situation.
Boric acid, which can be bought in a garden store, is a slow-acting insecticide. This is actually a good thing. Because it doesn't kill ants on contact like other insecticides, it gives the foraging ants time to bring the insecticide into the ant hill and kill the entire hill.
Combine 3/4 teaspoon of boric acid with either 2 ounces of peanut butter or 3 ounces of honey, depending on which type of bait the ants favored. Smear the boric acid-laced bait into the inside of a sealable container or jar. Close the container or jar, then poke three or four holes into the container's lid.
Place the container near the ant hill. The holes allow the ants to find and eat the bait while keeping out other animals. The ants will take the food back to their hill. Replace the bait as it's taken away until all ant activity has ceased.