NOTICE: Due to required system upgrades, online ordering will be unavailable 5/28-6/3. More Information »

Keeping Ants from Entering the House

Every year millions of homeowners endure a battle with ants. They seem to be everywhere and nowhere at once. They crawl across countertops. They circle a drop of spilled soda. They’re exploring the sink like tourists at the Grand Canyon!

But where are all of these ants coming from? How are ants entering your house? They seem to come from nowhere to exploit every housekeeping mistake you make. Let’s take a look at all the different ways that ants can get inside a home. Understanding how ants find their way inside is often the first step in treating an ant infestation, so let’s study these points of entry.

Cracks & Seams in Walls

Ants can get inside your home through cracks and other gaps. The pathways will continue to be used because foragers lay down pheromone trails that additional ants will follow.

Most homes aren’t hermetically sealed, meaning there is some air exchange between the inside of the house and the outside. This air exchange usually takes place along the seams of walls and windows as well as doors and vents. These gaps are large enough for ants to find a path into your home. Look for these seams where a wall transitions to a floor, ceiling or corner. Also check areas where holes have been created in a wall for awindow, outlet, plumbing pipe, electric line or vent.

Actual cracks can also invite ants inside your home. Some building materials - plaster and other older building material, for example - can develop structural splits that create a highway for these insects.

Foundation Gaps

Though most home foundations are strong, they are not always airtight because of gaps created during construction. It’s these gaps that provide ants just enough space to enter a home. Foundations that aren’t solid concrete blocks can also lead to spaces that persistent ants can penetrate as they search for food, warmth and moisture.

Inside the Floor

Sure, we all know that ants crawl on our floors searching for crumbs and other tasty treats. What may not be so obvious is that ants can travel inside your floor, too. They may have established routes underneath carpets, tile and hardwood flooring. Finding their entry point into a room can be especially difficult if they are coming under the surface of a floor covering.

At the same time, your subflooring may also be used by ants as they move through the house. Subflooring is usually made up of sandwiched pieces of plywood, and that creates plenty of space for a tiny ant to investigate.


While we appreciate the windows in our house for letting in sunlight and fresh air, they may also be giving ants access to your home. Open windows and screens with holes are easy for ants to move through. Beyond the window itself, the window frame may have gaps between it and the rest of the wall that permit entry for ants.

Window frames can also collect moisture and the wood can rot, meaning these areas can provide a home for several species of ants.


Just like you do, some ants will find the best way to enter a home is through the doorway. Doors that seal poorly are ideal for ants to gain access. Check the seal along the bottom of the threshold, but also check for quality seals on the sides and the top of the door, too. A door sweep may also help deter any invaders.

Another thing to consider is any door that is used infrequently. Since these doors see little activity, seals may deteriorate or cracks may develop unnoticed. These lapses can allow easy access for ants and other insects.

Utility Lines

With all the electricity, telephone, cable, water and natural gas lines, there are a lot of little holes in your house. Check where your utility lines enter your home for ant activity. Gaps where these lines connect to your home can be used by any small pest to get inside. Aside from pest issues, these spaces can let air into the home, which can be a strain on your heating and cooling budget.

Toys, House Plants & Other Articles

Ants may be brought into a house by mistake, too. For example, a hollow toy left in the yard over the summer can become host to an ant colony and then carried inside. Plants that are moved inside for the winter may also be the source of an ant invasion. Large groups of ants can also be brought inside on a variety of other articles, including used furniture or appliances, storage tubs, hoses, pipes and even groceries.

Born in the House

Of course, some ants have always been in your house. In fact, they may have been born there! That’s right; some ant species can build nests inside your home - often using wall voids or rotting wood to make a nest. That means you could have several generations of these insects joining you as tenants. In truth, foraging ants in such a colony probably do go outside. Other members of the colony, such as those that tend to hatching eggs or the queen, may not.

Ant Control Tips: 7 Ways to Keep Ants Out of Your House

Though ants have numerous opportunities to get inside your home, you have a lot of tools to use against these invaders. With a little work and help from TERRO®, you can stop the ants from coming inside. Try several of these control tips to get the best results in your campaign against these pests.

1. Exclude the Ants: Use silicone-based caulk to seal up any cracks or gaps that may allow insects to access the inside of your home. Your caulking efforts should be around utility lines, windows, baseboards, vents and other spaces that can be sealed. Once closed off, some of these areas can also be treated with TERRO® Ant Killer Spray for added protection from these ants. This indoor-outdoor spray kills on contact, and continues to provide killing power for up to 6 weeks. Other TERRO® products provide ant control as well, including granules and sprays. Be sure to read the label on these to understand proper use and application.

2. Tidy Up: Keep your countertops, floor and stovetop clean of any food debris that may entice ants to visit. This should include keeping pet bowls and indoor trash cans clean of any crumbs, grease or food particles. If your pet is allowed to eat whenever it wants, put its food bowl inside a pan that®s filled with a shallow pool of soapy water. This creates a watery gap the ants won®t cross.

3. Bait the Ants: TERRO® has learned how to use ants’ foraging habits against them. With TERRO® Liquid Ant Baits, you set a bait station near signs of ant activity and let the ants enter to find a sweet-tasting liquid. They happily eat this liquid and gather it to provide for their nest mates. These ants then lay a pheromone trail back to their nest that tells other foragers of their tasty find. Once back in the nest, the foragers share the liquid with the others ants. The sweet liquid, however, isn’t exactly what the ants expected. Instead of pure sugar, it’s infused with borax, which will eventually kill the foragers along with the other ants that consumed the bait. Baiting in this method, therefore, allows you to get rid of ants you see and ants you don»t see.

4. Remove Moisture: Patrolling ants are on the hunt for a source of water and moisture just as much as they are looking for something to eat. With that in mind, fix any leaky pipes, dripping faucets or clogged drains. By eliminating this attractant, ants will have one less reason to visit your home. If ants have taken up residence inside your home, you should also work to lower the humidity levels in the immediate area by adding a dehumidifier and fans. Doing so will dry up the wood these ants may be infesting.

5. Eliminate Shelter: Another way to keep ants out of your house is to eliminate areas outside where they can shelter or move about unimpeded. For example, keep mulch from piling up right next to your house. Instead, pull it a few inches away from the foundation. The same can be said for leaves and other debris that ants can hide under. Likewise, keep paving stones and other objects a good distance from the home. These objects serve as ‹caps› to nests, which keep the nests protected from predators and severe weather.

6. Try an Insect Trap: If you have found a particularly active entrance area for ants and have no good way to seal it, try placing a TERRO® Spider & Insect Trap across their most commonly used path. This sticky cardboard trap contains no pesticides and is easy to set up. Once the insects walk onto the sticky surface, they’re stuck.

6. Protective Barrier: Ants can also be stopped by creating a protective barrier around the outside of the house. Using the shaker bag, spread TERRO® Ant Killer Plus around your home’s perimeter. This product will kill ants and other insects on contact. TERRO® Ant Dust can be applied inside or outside the home. Outdoors, apply it uniformly around the foundation. Inside, spread it into hard-to-reach cracks and wall voids with a bulbous duster or dry paint brush. This waterproof powder can last up to 8 months, and creates a barrier around your home to keep ants and other insects away.

Cookies On This Site OK This site uses cookies to improve your user experience. By using this site you agree to these cookies being set. To find out more see our Privacy & Cookies Policy.
© 2022 Woodstream Corporation, Inc. All Rights Reserved.
29 E. King Street, Lancaster, PA 17602