How to Get Rid of Ant Colonies in Yard [8 Top Methods]

There are several ways to get rid of an ant infestation in your yard and kill ant mounds permanently. The best methods for getting rid of most species of ants are:

• Pour boiling water into the ant mound
• Spread diatomaceous earth on and around ant mounds.
• Place ant baits or use pesticides to kill ants.
• Sprinkle granulated ant killer near the mounds.
• Pour carbonated water on the ant mound.
• Mix vinegar and water as an ant mound killer.
• Flatten and compact ant mounds to drive out ants.

Each of these methods is effective at killing ants and driving them from your entire yard. We’ll review the benefits and drawbacks of each below, so you can get started eliminating ants right away.

How Hard is it to Get Rid of Ant Colonies in Your Yard?

The conical mound you see in your yard is only a tiny representation of the size of the active colony. Underground passages in an ant colony can extend to a depth of 4 feet (1.2 meters) and a circumference of 5 feet (1.5 meters). So, digging out the entire colonies isn’t really an option.

• Ant colonies spread several feet underground below the mound.
• An ant colony can be eliminated by killing the queen.

Ant colonies have a weak point: if the queen of the colony is killed, the colony of ants will die. The goal of the best anti-killing tactics is to kill the queen and wipe out the colony.

8 Ways to Get Rid of Ant Colonies in Your Yard

Lawns infested with ants can be saved in a variety of simple ways. The best course of action is to act fast, to stop entire colonies before they grow spread to take over more of your yard, or even your house. Any yard can be saved, but the sooner you kill an ant nest, the less work you’ll have to do.

Boiling Water

A simple and low-cost solution. Boiling hot water poured into a nest kills ants on contact, and water that remains in the nest drowns ants and larvae, including the queen.

• Boil 1/2 gallon (2 liters) of water.
• Rake away the top of the ant mound.
• Pour boiling water into the main entrance to the colony.
• Repeat boiling water application within 12–24 hours.
• Keep in mind, boiling water may kill any plants or grass that it is poured on.

Because some ant species can survive a remarkably long time underwater before drowning, it is beneficial to repeat the boiling water treatment within a day of the first application. This method can also be hit-or-miss, so try another method if you still have a colony of ants in your yard.

Diatomaceous Earth

Diatomaceous earth is a chemical-free ant killer. It is made from the fossilized exoskeletons of tiny organisms called diatoms. When diatomaceous earth comes in contact with ants, it robs them from sources of moisture, drying them out and killing them. To use diatomaceous earth to kill an ant mound:

• Rake or shovel away the top of the mound and break up the earth beneath.
• Pour this diatomaceous earth onto the ant nest.
• Using your rake or shovel, mix the diatomaceous earth into the soil.
• Pour additional diatomaceous earth on top of the destroyed mound.
• Diatomaceous earth won’t harm plants, people, or pets.

This tactic will destroy the mound and drive ants out, preventing them from rebuilding their colony.

Ant Baits

Outdoor commercial ant baits are a great way to strike directly at the queen ant. Liquid ant baits are an ideal solution. To use commercial baits:

• Place an ant bait station within a few feet of the mound you wish to kill.
• The poison bait will attract the worker ants, who mistake it for food.
• The workers will feed the bait to the queen. The slow-acting poison will kill both the workers and the queen.

When using commercial insecticides or baits to destroy ant colonies, be careful to ensure pets and children are not exposed to pesticides and poison. Some pets may be attracted to the scent trail and taste of ant bait.

Granular Ant Insecticide

You can use a granular insecticide to kill ant mounds. This method is very similar to using any baits. To apply granular insecticide:

• Sprinkle this granular ant killer near the mounds in your yard.
• Ants will mistake the poison for food, and carry it back to the colony.
• Within a few days, the active colony should be eliminated.

One of the benefits of using a granular ant killer is it won’t cause harm to your grass and lawn. But similar, to batis, pets might be attracted to the granules, so keep them off your lawn until you’ve eliminated the ant problem.

Pesticide

If you’re dealing with invasive fire ants or other common species with harmful bites, you’ll want to attack quickly. Choose an ant killer that stops fire ants and other species dead and prevents them from coming back. For a pesticide application: 

• Water the mound area the night before treatment.
• Spread your chemical pesticide on each individual mound and the surrounding area.
• Water the mound killer into the ground, as directed on the product label.

This simple to use product will kill ants, including the queen, quickly. You can eliminate even the most stubborn ant mound this way.

Carbonated Water

Carbonated water is an extremely effective ant killer. If you pour regular water into a mound, there may be air pockets below ground where the ants can cluster safely. The carbonation of sparkling water actually drives oxygen out of the ant mound, suffocating any ants that find an unflooded tunnel.

• Rake or shovel away the top of the ant mound.
• Pour 2 liters of plain carbonated or sparkling water on the ant mound.
• Repeat carbonated water application within 24 hours.
• Won’t harm plants and grass.

Many swear that room-temperature carbonated water is far more effective than plain boiling water. It’s a cheap and simple option for killing ant hills and poses no risk to surrounding plants.

Vinegar and Water

Vinegar kills ants on contact but is not a toxic chemical. You may have the ingredients in your home to make an ant mound killer right now. To kill ant mounds with vinegar:

• Mix 4 cups (1 liter) water with 4 cups white vinegar.
• Pour mixture into ant mound.
• Repeat within 24 hours.
• Vinegar and water mix will kill grass and plants it comes in contact with.

This vinegar mixture is strong enough to kill ants, as well as any plants it is poured on, but isn’t powerful enough to harm people or animals. It is safe to use in your family’s yard.

Flatten Ant Hills

It may seem too simple, but destroying any mounds and compacting the ground to block mound entrances can be enough to starve out ants or drive them from your yard. The best way to flatten an anthill to prevent ants from returning is to follow these steps:

• Use a rake or shovel to destroy the top of the mound.
• Dig and turn the top 6 inches of dirt in a one-foot radius around the mound entrance.
• Tamp down the turned dirt with a shovel, tamper, or by stomping on it.
• Water the tamped earth to ensure it settles.

This process will destroy the upper tunnels of the colony of ants, trapping ants inside. An ant colony attacked in this way is likely to die. If any ants survive, they are likely to view the area as unsafe and flee the colony.

How Do You Get Rid of an Outdoor Ant Infestation in Your Yard?

To wipe out any type of ant mounds and kill the queen you can pour any one of the following into the mound: boiling water, room-temperature carbonated water, or water mixed with vinegar. All of these solutions require little effort and can be made with simple household products.

To wipe out stubborn ants, outdoor liquid baits and granular ant killers are very effective, as is applying a pesticide mound killer and watering it into the soil. If you want to use a natural ant poison that won’t harm children or pets, mix diatomaceous earth into a destroyed mound to kill ants. If you want to skip these products altogether, dig up ant mounds and flatten the soil to trap ants inside. Each of these solutions is cheap and works to drive out harmful pests fast.