Unfortunately, there are plenty of things that can make your basement an attractive home to insects, and one species of scavenger insect is a particular nuisance: ants. So, what should you do if ants invade your basement?
If you’ve got ants in the basement, you can use an insecticide or place bait traps near ant trails to eliminate the colony. Make sure that any food in the basement is stored securely, seal all entry points, and if you place bait traps put them where pets can’t get to them.
Your friends and family will likely offer this or that home remedy for ants. But unfortunately, many of the popular methods are ineffective and ants will come back again. So instead, let’s look at the problem on a broader scale and explore the correct ways to deal with ant infestations in your basement.
Why do ants love basements?
Ants are attracted to basements for several reasons. Perhaps the most important is that basements are often relatively damp and dark, providing a suitable environment for ants to establish a colony.
Additionally, basements often get used for storage. As a result, they may contain food sources such as sugar, cereal, and other dried goods that ants find particularly attractive.
Another reason why a basement might be targeted is that it’s physically closer to an ant colony. As a result, it’s easier for the ants to get to the basement, and it may have a crack or hole that they can use to easily enter the building.
Ant colony in Your Basement: common signs
Several signs can indicate the presence of ants in your basement. If you see ants crawling around in your basement, they have almost certainly established a colony there (or nearby).
Ants leave a chemical trail for other ants to follow. So if you see a line of ants marching in and out of your basement, that could also signify an infestation.

Ants will often establish a nest in a secluded area of your basement, such as behind a wall or in a corner. Look for small mounds of soil or piles of debris that may indicate a nest.
Ants can cause damage to structural wood or other materials. Look for small holes or gnawed wood.
Certain types of ants, such as carpenter ants, may also emit a musty odor when they’re present in large numbers.
Remove Ants From Your Basement: 10 essential tips
If you’ve identified an ant problem in your basement, it’s time to take action. Let’s take a look at how to proceed so that you can regain control of your space.
1. Locate the Colony
As we mentioned above, ants typically establish colonies in secluded basement areas, such as behind walls or corners. Identify the location of the colony so that you can target it specifically.
The easiest way to do this is to put out bait and follow the trail back to its nest. Something like Peanut Butter or Bacon grease will leave an easy-to-follow trail. Other signs are a pile of dead ants (which could indicate a nearby nest) or locating other dead insects that ants could have taken back to their nest.
Top tip: Check for cracks or crumbling basement walls and knock on the wall to establish if it’s hollow, and maybe housing an ant nest.
2. Eliminate Food Sources
Ants are attracted to food sources, so removing any food that may be accessed in your basement is important. Clean up crumbs and spills, store food in airtight containers, and clear any food preparation areas immediately after use. Ants love sweet food, animal fat, and meat products so eliminate these at all costs!
3. Use Bait Traps

Ant bait traps work by luring ants to the bait with sweet or protein-based food. Once the ants have consumed the bait, they will return to their colony and transfer it to other ants. Eventually, this behavior will eliminate the colony.
Purchase ant bait traps (on Amazon) to use in your basement. Make sure to choose a bait trap labeled for the type of ants you have (more on that below).
Place the bait traps near any ant trails you might find, or near the colony if you’ve found one. This will increase the chances of the ants finding the bait.
Monitor the bait traps. Check them regularly to see if they need to be refilled or replaced. Once the bait traps are full or no longer effective, dispose of them properly, following the instructions on the package.
It may take several days or even weeks for the colony to get eliminated. It’s important to use the bait traps in conjunction with other control measures, such as removing food sources and sealing entry points.
That will help prevent new colonies from forming or other ants from entering your home.
4. Use an Insecticide
You can spray an insecticide (on Amazon) or use a powder or granules to kill the ants in your basement, but follow the instructions on the label carefully.
While this can be done without prior experience, it’s sometimes best to contact a professional pest control company to properly identify the species of ants and implement a treatment plan.
Note that different species of ants have different behaviors and food preferences. Therefore, it’s important to know which type of ants you have before taking any steps to eliminate them. Certain insecticides are more effective in eliminating certain species.
Here are a few examples of common ant species and the insecticides that are known to be effective against them:
Carpenter Ants

Carpenter ants don’t usually nest in the home, but they do like nesting in decaying wood. So if the structure of your house is decaying, and you’re seeing very large ants come and go, it’s possible you have a carpenter ant infestation in your basement.
These ants can typically be controlled with a combination of baits and liquid insecticides. For example, boric acid (on Amazon) and borax-based baits are known to be effective against carpenter ants.
As for poison, these ants are susceptible to liquid insecticides containing pyrethrins, permethrin, or cyfluthrin.
Fire Ants

Fire ants are more prevalent in the Southern states and you’ll typically find these red ants outside or on the driveway. If you have easy outdoor access to your basement, it could be easy access for fire ants. They like hot areas and build mounds outside, but do occasionally come inside. You’ll know it’s a fire ant if you get stung, as it’s sharp and fiery!
You can control fire ants with baits that contain the active ingredient methoprene or hydramethylnon. These baits are typically made with a mixture of food and insecticide and are placed near the ant mounds.
Odorous House Ants

Odorous ants are small and dark brown and are commonly found in floorboards, so it’s very possible that the infestation in your basement is odorous ants.
These ants are attracted to sweet foods, so baits made with sugar or syrup and an insecticide, such as borax, are typically effective. They are also one of the most common ants found in the home.
You can also use a liquid insecticide containing pyrethrins or permethrin.
Argentine Ants

Argentine ants are found in California and may shelter in your basement during Spring when it’s too rainy outside.
Argentine ants are attracted to greasy and fatty foods, so baits made with peanut butter or bacon grease and an insecticide can be effective.
You can also use a liquid insecticide containing pyrethrins or permethrin.
Pharaoh Ants

Pharoah ants like warm, humid areas near drain pipes or water.
Pharaoh ants are attracted to sweet foods, so baits made with sugar or syrup and an insecticide are the way to go. You can also use a liquid insecticide containing pyrethrins or permethrin.
Note: Baits can take a while to work, and you may not see any results immediately. Also, when using any insecticide, always read the label carefully and follow the instructions to avoid any damage to your basement or physical harm.
5. Keep Things Clean
Regularly cleaning and vacuuming the basement can help to remove crumbs and other food sources that ants may find attractive.
6. Store Food Properly
As you can see, food is a major player when it comes to ant infestations, and one of the best ways to deal with them is to keep your food stored properly. Here are some tips to follow:
Keep All Food in Sealed Containers
Use airtight containers or resealable bags to store food items. That will prevent ants from getting in and protect your food from other pests like cockroaches.
Store Food in a Refrigerator
Keeping perishable food items in the refrigerator or freezer can also help to keep ants away, as they’re less likely to be attracted to cold temperatures. If you store food in your basement, consider installing a dedicated refrigerator to keep food down there.
Clean Up Spills and Crumbs
Ants are attracted to sugar, grease, and other food debris, so keeping your basement clean and free of spills and crumbs is important.
Store Food Off the Floor and in a Bug-Proof Pantry
Keep food on high shelves or cabinets to make it more difficult for ants to access it. Installing the appropriate storage space can help prevent an ant infestation.
Consider using a bug-proof cabinet to store food. These are designed with tight-fitting doors and screens to prevent ants and other pests from getting in.
Keep Food in the Original Packaging
To prevent ants from entering food packaging, try not to open the food packaging before you’re ready to use it.
7. Seal Entry Points
Look for cracks or gaps in your basement’s walls, floors, and foundation. Pay special attention to areas where utility lines enter the building.
Use silicone or acrylic caulk (on Amazon) to seal all cracks and gaps. For larger openings, use a foam sealant. Be sure to smooth the sealant out, so that it’s flush with the surface.
Look for other potential entry points, such as vents or window wells. Make sure these areas get properly sealed as well.
8. Keep the Humidity Low
You can use a dehumidifier (on Amazon) to remove excess moisture from the air in your basement. Be sure to empty the water tank regularly and clean the filter to ensure the dehumidifier runs efficiently.
Open windows, use fans or install vents to increase airflow in the basement. That will help to remove moist air and bring in dry air from the outside.
Also, insulate any cold water pipes in the basement to prevent condensation from forming on them, and install a moisture barrier on the walls and floors of your basement to prevent moisture from seeping in.
Check your basement for leaks and repair them as soon as possible to prevent moisture from entering the basement.
Use a hygrometer (on Amazon) to monitor the humidity level in your basement and make adjustments as needed.
Keeping the humidity low in your basement may be difficult if the humidity outside is high. In such cases, it’s important to keep the windows closed and use an air conditioner to cool the basement.
9. Don’t Leave Standing Water
Standing water can attract ants, so fix any leaks and remove any standing water from the basement.
10. Keep Vegetation Away
Ants often nest in or around vegetation. Trim any bushes or trees close to your home and keep the area around your foundation clear.
Professional Help
If you notice a particularly bad ant infestation, it’s best to contact a professional pest control company to properly identify the species of ants and implement a treatment plan.
Preventing ant infestations is important to maintain a healthy and hygienic home environment. Therefore, it’s important to be vigilant and take the necessary steps to keep ants out.