Ants In Basement – What To Do?

Ants can appear when they find food sources. Failure to keep these insects in check can result in infestations. So what can you do if you find ants in your basement? We researched and consulted with bug experts, and here’s what they told us.

To get rid of the ants in your basement, follow these steps:

  1. Search for and block the ants’ path.
  2. Kill the insects that remain with a soapy sponge.
  3. Use bleach and wipe it on the ants’ remains to remove leftover pheromones.
  4. Locate the ant colony and place a trap near it.

If you find it more challenging than intended to eliminate certain ant species from your basement, you may need to request professional help. Moreover, applying preventive measures can help ensure that the ants don’t return to the property. Keep reading to learn more about how to prevent these pests from wreaking havoc in your home.

A gun target on ant at home, Ants In Basement - What To Do?

How To Get Rid of Ants In Your Basement

The first step to eliminating ants in the basement is to identify the ant species. Certain ants don’t respond well to traps, which means you may need to employ special methods to take them out.

However, if you’re dealing with fairly common household ants, we have listed the materials, tools, and steps to get rid of them below:

Ants in the house

What You’ll Need

  • Tape
  • Sponge
  • Soap
  • Water
  • Bleach
  • Bucket
  • Vacuum cleaner
  • Broom and pan
  • Commercial ant trap

Step-By-Step Guide

  1. Follow the trail of ants to locate their nest. If you can’t find the ants’ breeding ground, the next best thing is to find their entry point. Block the ants’ path by using things like tape to create temporary blocks in cracks.
  2. Apply a wet soapy sponge on the remaining ants to kill them. Repeat this step until you no longer see signs of the bugs.
  3. Use a diluted bleach solution to wipe the pheromone the ants leave behind when they die.
  4. If you can find the ant colony, place a commercial bait trap near it.
  5. The extermination may leave behind a significant amount of dead ants in the basement. If so, use a vacuum for the final cleanup. Otherwise, a broom and pan should suffice.

Take note that if you’re dealing with carpenter ants in your basement, it might be best to contact a professional exterminator. Carpenter ants, along with other species, don't respond well to traps.

Also, watch the video below to help you eliminate black ants on your property:

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How Do You Prevent Ants From Entering Your Basement?

Closeup shot of ants colony walking on the whitewashed wall surface

Preventive measures are necessary to ensure that ants won’t return to your basement and the rest of your property. Here are some quick tips to help keep these pests away from your house.

  • Sweep, mop, and vacuum surfaces to remove food and crumbs from the floor.
  • Put away pet food bowls after the animals finish eating.
  • Don’t keep trash in garbage bins for extended periods.
  • Keep the plants surrounding the basement’s foundation trimmed.
  • Repair leaks, as some ant species find moisture attractive.

Additionally, you should also cover the cracks and gaps in the basement ceiling, floor, and walls to prevent ants from entering. Find out more about sealing these surface imperfections by reading this post: Can You Fix A Leaky Basement From The Inside?

Where Do Ants Come From In The Basement?

Ants can enter a basement from different entry points. These access points include:

  • Cracks in walls: Some hairline cracks are sufficiently large for ants to crawl through and gain access to your basement.
  • Foundation gaps: Foundation issues, such as soil dehydration, can introduce gaps in the foundation, allowing ants to enter the subterranean space.
  • Subflooring: Ants may want to live in the sandwiched space between the earth and floor.
  • Windows: Unsealed windows often have gaps that allow ants and other small insects to get through.
  • Doors: Like windows, a poorly sealed doorway can provide access to these pests.
  • Objects in the yard: Houseplants, toys, and cups left in the lawn can become new ant nests, which can lead them to your basement.

For more information about preventing other insects from entering the basement, read this post: How To Prevent Bugs In A Basement Apartment?

Can Ants Live In Concrete Walls?

Large Ants collecting a cereal ball

Certain ant species like the pavement ants (Tetremorium caespitum) usually live in concrete, particularly in walls. These ants often build their colonies near garages and homes, especially in places where concrete slabs are fairly abundant.

Moreover, these pests like to huddle indoors during the winter, which may increase the risks of infestations during this season.

Take note that pavement ants are dark brown to black. Plus, this specific ant classification is about 1/8-inch long. Dealing with a pavement ant infestation may only require you to use a protein- or sugar-based trap.

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Can Ants Get Under Foundation?

Certain ant species can burrow and travel up to 30 feet underground to search for suitable living spaces. These insects can enter and weaken foundations as they build their colonies. Then, the ants can enter homes through different access points, including insulation, floors, and walls.

One particular ant species to be wary of is the fire ant (Solenopsis). This type of ant often likes to build its nest near structures such as fences and exterior walls. A fire ant is generally aggressive and will sink its pincers into things that it finds threatening.

How Do I Get Rid Of Ants In My House Foundation?

You'll need caulk or cement mix, pesticide spray, and ant baits. Once done preparing the materials needed, you can proceed to kill persistent ants living near and in your house’s foundation by following this guide:

  1. Remove debris and rotting wood from the property’s perimeter.
  2. Repair hairline cracks with caulk, and use cement patch mixes for large gaps and holes.
  3. Set ant bait traps near ant colonies around the settlement.
  4. Spray the foundation with pesticides.

Take note that using harsh chemicals around the property may also bring harm to other organisms such as plants and other helpful insects. If you don’t want to use dangerous compounds to kill ants in the foundation, you can use eco-friendly alternatives (which will be discussed in the next section).

What Is The Best Homemade Ant Killer?

Some relatively common household items can turn into fairly effective ant killers. These items include:


Many ants cannot stand vinegar and will actively avoid it. Vinegar has a strong smell that can throw off an ant’s senses. The excess moisture from this solution might drown some of these pests. Although it's not a great ant killer, it often does a great job of keeping these insects at bay.

Create a vinegar spray by mixing a cup of this ingredient with a cup of lemon juice. Put the concoction in a spray bottle. Then, spray the solution in areas with an abundance of ants.

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Essential Oils

Like vinegar, ants can’t stand the strong smells of essential oils like peppermint, citrus, and tea tree oils. Mix these products in a spray bottle with 4 ounces of white vinegar. Spray the solution in your basement or in other areas that require ant cleanups.

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Borax is a white, powdery substance widely used as a household cleaner. Aside from being a fairly effective toothpaste and skincare ingredient, this compound can also become an efficient ant killer.

Mix ½ cup of sugar and 1-1/2 cups of warm water with 1/1-2 tablespoons of borax in a small, disposable bowl. Place this eco-friendly ant trap near a colony. The ants will gather and take this solution back to their nest. Borax is poisonous to ants and can even get rid of their queen if she eats it.

However, some ants may not find this borax trap enticing. If so, add ¼ cup of syrup and a cup of sugar to the mixture.

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Food-Grade Diatomaceous Earth

Diatomaceous earth is a powdery product made from fossilized algae sediments. The moderate use of this product is fairly safe for humans. However, be mindful, as breathing a significant amount of diatomaceous earth may induce adverse respiratory reactions like asthma attacks.

The use of food-grade diatomaceous earth in eliminating ants is reasonably straightforward. You only need to sprinkle a light and thin layer of the substance on ant trails or over colonies. The particulates will disrupt the ants’ organs, which ultimately leads to their demise.

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Baking Soda

Mix baking soda and powdered sugar of equal parts into a small bowl. The ants will become attracted to the sugar, but they should also take the baking soda back to their nest. Once eaten, the baking soda will create carbon dioxide bubbles in the insects’ bodies, exploding the infected pests from the inside.

Final Thoughts

Ants can enter the basement and foundation through places like gaps in the walls and unsealed windows. Getting rid of these insects requires you to find entry points, block paths, and remove the pheromones that attract their kin.

Additionally, you may want to use a protein- or sugar-based ant bait trap to take out the pests. However, some species, such as the construction ants, don’t respond well to these lures. If so, you should call a professional exterminator if you don’t know how to deal eliminate these insects.

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