Categories: Residential and Urban Services, Carpenter Ants

There are certain things people expect in the winter - snow, ice, wind, and freezing cold weather.

Ants in the winter...not so much.

But ants can be an issue inside homes in the winter. Here in Ontario, the most common types of ants in the house in the winter are:

Carpenter ants are the most common and problematic of the bunch. Carpenter ants nest inside wood and can cause severe and costly damage to a home’s structure. Learn more about ants in our Pest Library, including some interesting facts about ants, and more tips for how to get rid of ants.

a group of carpenter ants on a wall inside a home


This time of year, most of the ant infestations we help with are discovered by homeowners:

  1. During really nice warm sunny winter days when an unknown leak in the house has caused water to back up and wake up a nest of dormant ants or disturb a colony of still active ants. These ants are then found in the kitchen crawling around the floors, windows or on the counter or they are spotted in the bathroom, on walls, floors, in cabinets, and even in the sink, tub or shower stall.
  2. During home renovations, often when installing new windows or doors.

Upon discovering an ant infestation in the house, most homeowners are caught off guard, especially if they directly disturb a large nest and witness thousands of ants starting to pour out of a wall void (which is very common with carpenter ant infestations). It’s really hard to believe that so many ants have been living inside your home and that you had no idea...but it happens often. 


Why Do I Have Ants in the House in the Winter?

Ants can be an issue any time of the year, but when you discover ants inside your home (or your business) in the winter, this is often a sign that you have an ant colony living in your home.

How did they get inside?  Ant colonies are predominantly outdoors, but ants do migrate inside structures, like homes and businesses, in the spring, summer and fall, as they forage for food and water sources. If the ant colony was in your yard, or in your driveway adjacent to your home, while seeking out food they could find their way inside through exterior cracks and crevices. Inside homes, ants most commonly nest in wall voids, door frames, window frames, ceilings, insulation, under floors, behind cabinets or baseboards. Carpenter ants, who are attracted to moisture, favour nesting where condensation collects or leaks are likely, such as pipes, drains, kitchens, and bathrooms, and around windows and door frames.

Now, while ants typically don’t intend to build their colony inside a home or business, this does happen ants have found a way inside, and the conditions are habitable - it’s warm and provides a sustainable source of food and water.

Here’s a common and real-life example of how ants get into a home, and how an infestation is discovered:  A home had an exterior crack under the siding near a window, which slowly let water drip into the wooden window frame without any signs that there was an issue. Over years, the wood under the siding began to decay from the continual dampness, making it the perfect habitat for carpenter ants. Because there was already a crack in the exterior, carpenter ants did get inside the home in search of food, and they found the perfect habitat to build a colony. During a new window installation, upon pulling out the frame, it was discovered that the wood was fully rotted and infested with thousands of carpenter ants.


Are Ants Dormant or Active in the Winter?

In the winter, an ant colony in your home could be partially dormant, or still active. If their nesting area is too cold, they can enter a dormant like state until they are disturbed. If an ant colony is in a warm spot with ample food and water, like in the kitchen near an active appliance, the colony could remain active all winter long and grow in size.


What’s the Best Way to Get Rid of Ants in the House?

Step 1: Identify the Ant Species

If you discover ants inside your home in the winter, call a licensed ant pest control professional, like Environmental Pest Control. Why? Because the most important thing that an ant exterminator will do is help you properly identify the ant species infesting your home and administer the proper indoor treatment. Why does this matter? Different types of ants require different types of treatments. For example, when getting rid of ants inside a home, an indoor spray treatment will be effective on carpenter ants, acrobat ants and pavements ants, but not on pharaoh ants. To get rid of pharaoh ants, bait treatments are needed. 


Step 2: Track the Ants & Locate the Nest

Once our ant exterminator knows the type of ant they are dealing with, they will next track it to try to locate where the nest is. Depending on the type of ant, and how long an infestation has gone on unnoticed, there could be multiple nests. Locating the nest can be challenging, but it is very important in getting rid of ants in the house.


Step 3: Interior Ant Treatment

Once they identify where the nest is, they will be able to administer the right interior treatment to help get rid of ants. Here at Environmental Pest control our products are eco-friendly and safe for people and pets.


Step 4: Exterior Treatment in the Spring for Prevention

When you have ants in the winter, the interior ant treatment only helps get rid of the ants that are already in your house. The ants got into your house somehow, and if that issue is not resolved or addressed then it is possible that ants will get into your home again, a re-infestation is possible. This is why we always recommend an annual exterior ant treatment in the late spring. In the winter it’s impossible to do an exterior treatment because of the snow and ice buildup around homes.  Exterior ant treatments are an effective way to prevent ants from getting back into your home and are an effective means of prevention.


Get Professional Ant Pest Control Help

If you discover ants in the house in the winter, give the team here at Environmental Pest Control a call. We’ve been your local trusted ant pest control experts since 1988! If you have ant issues, we have effective solutions.


Call 1 (800) 263-5055

Our Professional Team is Happy to Help!