Ants: How to Get Rid of Ants in the House | The Old Farmer's Almanac


Photo Credit
No content available.

How to Get Rid of Ants in the House

Print Friendly and PDF

Crumbs moving independently across the kitchen floor? A line of small black things crawling in and out of your trash bin? Looks like you have an ant infestation. Here’s how to get rid of ants in your home—and prevent them from returning!

Ants as Pests

Ants play an important role in nature, but most of us can agree that they don’t belong in people’s homes. Nonetheless, ants are among the most frequent household pests. There are about 1,000 known ant species in North America and over 12,000 species worldwide.

In the outdoor world, ants are generally beneficial insects. They mostly live in the garden and help aerate the soil. In addition, they are scavengers, helping to reduce the numbers of other insects—including those we consider pests. Ants are part of the insect order Hymenoptera and count bees and wasps among their relatives.

In the indoor world, there are only a few speces that come into people’s homes. They’re not generally dangerous—just annoying.


How to Identify Ants

Though ants are familiar insects, in the home, they are sometimes confused with termites. If you look closely enough, you can tell an ant by its slim middle and curved antennae. Termites have thick middles and upright antennae.

The body of an ant is divided into three sections: head, thorax, and abdomen. An ant’s middle may have one or two segments, or “nodes.” This feature divides ants into the aptly named groups of one-node and two-node ants.

As with bees, ants’ colonies are largely female. Wingless adult ants are the colony’s workers, who are in charge of gathering food, feeding larvae, sustaining the nest, and protecting the colony. The colony queen’s only job is to lay eggs. Male ants have wings and mate with the queen.

Common House Ant Species

Carpenter Ants

Carpenter ants are large, ranging from 1/4-inch to 5/8-inch long. They are dark brown or black, but some species may have red or yellow coloring.

When carpenter ants build their nests, usually in damp or decaying wood, they dig out tunnels which weakens the wood from the inside. You’ll know you have these pests by the appearance of small holes on the surface of wood and by the debris they produce from tunneling.

Eastern Black Carpenter Ants. Photo by Ryan Hodnett/Wikimedia Commons
Eastern Black Carpenter Ants. Photo by Ryan Hodnett/Wikimedia Commons

Odorous House Ants

Odorous house ants are only about 1/8-inch long and have beehive-shaped abdomens. They are dark brown or black.

When threatened or crushed, odorous house ants give off a smell of rotten coconut, hence their name. While these ants do not pose a public health risk, they can contaminate food.

Little Black Ants

Little black ants are 1/16-inch long with two-segmented abdomens. They can be dark brown to black, but usually very dark black. These ants are shiny.

While little black ants don’t pose a threat to our health, they can be a nuisance and contaminate food.

Control and Prevention

What Attracts Ants To Your Home?

The most common reason for ants to venture inside is in search of food. They love it when you leave dirty dishes in the sink, don’t wipe up sticky countertops, and leave crumbs on the floor. They also enjoy pet food as much as your dog or cat. What starts with a few ants feasting on the juice that never got wiped up off of the floor can turn into a real pest problem. It only takes one ant to discover a smorgasbord of crumbs and then ring the dinner bell for the rest of the colony!

Though most ants rarely cause significant damage or harm, their abundant numbers can become a nuisance.

How to Stop an Ant Infestation

The first step in stopping an infestation is to determine where the ants are invading from—perhaps a poorly sealed window, a crack in the baseboard, or a gap in the doorframe? When you see ants, don’t squish them; let them lead you to their entry and exit point.

Once you determine how the ants are getting in, consider doing the following:

  1. Use soap and water to wipe up ant trails or chemical paths. As ants explore, they leave behind a trail of pheromones, which helps their fellow ants know where to go. Destroying this trail will prevent other ants from finding their way in.
  2. Dust around infested areas with diatomaceous earth. DE is an abrasive material that will dehydrate any ants that come in contact with it.
  3. Find where the ants are entering your home and mark the area with chalk. Chalk contains calcium carbonate, which ants dislike.
  4. Find where the ants are entering your home and cover the area with ground black pepper, salt, peppermint, or white vinegar. Ants do not like bitter tastes and strong, sour smells.
  5. Borax, a boron compound, is an effective method of controlling an ant infestation. It’s a natural substance that is non-toxic to humans when used properly and poisonous to them when ingested. But ants are not attracted to Borax itself, so you have to mix it with something tempting to ants such as sugar. 
  6. Alternatively, use liquid ant bait traps, which are specially formulated to attract ants. Place baits close to visible ant trails but outside the reach of pets and children When the ants carry the bait food back to the nest, the other members of the colony ingest it.The bait will work most effectively if you keep other surfaces clean so that the bait is the only sweet substance available to attract the ants.
  7. Avoid the temptation to use pesticides inside the home. They may eliminate a few visible ants, but the queen ant (sheltered inside the wall) will quickly make more work ants to replace them. Also, pesticides are chemicals that also kill helpful insects, such as bees and predatory insects.

How To Prevent Ants From Entering Your Home

Once you’ve stopped an infestation, it’s time to ensure that it doesn’t happen again.

  • Be diligent about picking up crumbs and cleaning up spills, especially sugary, sweet liquids like lemonade, juice, and soda.
  • Keep floors swept, rugs vaccuumed, and all counters clean.
  • Keep food sealed. Use food bags tightly closed or consider using hard, sealed storage containers that can’t be easily chewed through, like glass or plastic.
  • Store ripe fruit in the refrigerator.
  • Clean up pet food as soon as pets are done eating.
  • Empty and clean garbage cans and recycling bins frequently.
  • Vacuum up ants when you see them and dispose of the bag as soon as you are done.
  • Seal cracks and crevices that ants may be using to enter your home. Seal around windows and doors and all cable, pipe, and wire entry points.
  • Keep firewood stacked at least 20 feet away from your home, as ants may see this space as a perfect place to put their colony!

We hope you found this advice helpful.

See our related article on how to keep rodents (mice and rats) and squirrels out of the home.

2023 Almanac Club