Ant Hills in Grass: How to Control Ants in Lawns
Ants are generally not considered dangerous pests, but they can cause significant health and cosmetic damage to turf grass. When ant hills cause root damage and create unsightly mounds, they become a problem.
Ants create numerous generations per year, and their colonies can number in the hundreds or thousands. They nest underground in intricate labyrinths built within the root systems of grass, where they feed their young and protect the queen. The entrances to these nests are marked by mounds of dirt, which can pose hazards to foot traffic, mower blades, and lawn-related sports like golf.
Are Ants in Your Lawn Always Bad?
Discovering a nest in the lawn often prompts immediate action, but ants do little damage to grass, preferring to dine on other things. In fact, ants can be beneficial by removing larvae of damaging turf pests. Field ants, however, can create large mounds that are unsightly and hazardous. Despite this, ants are not typically the cause of poor turf grass performance.
A healthy colony of ants can naturally control other pests that harm lawns. Many ant species “farm” pests like aphids and mealybugs to maintain a honeydew source.
When Are Ants a Problem in Grass?
Outside of aesthetic issues, ants can disrupt golf courses due to the low mowing height and the need for pristine conditions. Ant mounds create uneven ground, interrupting smooth golf putting. Excess soil from mounding can smother turf grass, and tunneling removes soil from grass roots, causing them to dry out and die. Ant tunnels can delve 4-5 feet below the surface, potentially destabilizing areas with high colony concentrations. Some ant species also deliver painful bites if disturbed.
Ants tend to nest in sparse, sunny locations. In healthy, thick grass, they rarely colonize.
Lawn Care and Ant Hills
Ant hills are most noticeable from May to early September, with peak activity in June. Ants prefer sandy soil for easy tunneling. To prevent ant hills, maintain a healthy lawn by mowing to a height of 3 inches, watering deeply, and fertilizing annually. A thick lawn is less attractive to nesting ant queens, who prefer dry, well-drained soil in low-traffic areas.
How to Control Ants in Lawns Naturally
Eradicating ants in lawns requires killing the queen, which is tricky due to the use of lawns by children and pets. Ant populations can vary greatly, and large colonies may necessitate eradication efforts.
Raking
For low ant populations, regular raking can scatter the ants and reduce mound formation. This is effective when done weekly from fall to summer.
Borax
Borax, a naturally occurring mineral salt, can be used to control ants. Mix equal parts sugar and warm water with a couple of teaspoons of Borax, soak cotton balls in the mixture, and place them near the nest. Alternatively, sprinkle borax powder around the mound. Borax dehydrates ants once ingested, but it can be toxic, so keep children and pets away from treated areas.
Dish Soap
A 3 percent dish soap solution with water can be sprayed on infested areas. Adding a spoonful of vegetable oil can enhance its effectiveness.
Diatomaceous Earth
Sprinkle diatomaceous earth in and around the mound area while wearing a protective mask. This substance is harmful when inhaled, so take precautions.
Other Ant Treatments for Lawns
Chemical treatments are rarely recommended but may be necessary for stinging ants. To kill the queen, use granular ant baits or pour liquid controls directly into the nest. Products with deltamethrin, bifenthrin, and permethrin are effective if they penetrate deeply into the soil. Spot control is best, as it minimizes damage to beneficial insects.
Apply chemicals as indicated on the label and irrigate granular forms after application. Ensure treated areas are dry before allowing children and pets into the area.
Ants can be both beneficial and problematic. Consider the severity of the problem before resorting to chemical treatments. Their activity can naturally aerate soil and enhance plant growth.
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