How to Get Rid of Carpenter Ants in Your Home

We share the world with lots of living things. Some of them share our homes, like cats, dogs, fish, and even ferrets. However, others we’d rather not have in our kitchens, bathrooms, and bedrooms: centipedes, roaches… and ants. Carpenter ants in particular are problematic because they damage wood and, by extension, houses and buildings. We’ll teach you how to identify if they’ve taken up residence in your home and how to remove them. 

What are carpenter ants? 

Carpenter ants are larger than an average ant, ranging from 6 mm to 25 mm long (anywhere from a stack of three nickels to slightly bigger than the diameter of one). They live in colonies much like bees do with one or more queens, several others that reproduce, and tens of thousands of sterile female workers. 

What do carpenter ants look like? 

Well, they look like other ants in that they have antennae, six legs, and three distinct parts to their forms: a head, body, and thorax. However, carpenter ant identification is fairly easy because they come in two different colours: black (darkish brown really) and red (darkish brown with a reddish-brown upper body).  

Their antennae are also bent in the middle and can look a bit like a jointed set of bull’s horns (if you can get one to stand still). They can have wings if you catch them during their mating times. One other feature that sets them apart from most other ants is that they bite. Not hard, mind you, but enough to notice.

How do I know if I have termites or carpenter ants? 

For starters, carpenter ants don’t actually eat the wood they burrow through: they throw it out of their nests. So, if you have them in your house, chances are you’ll see the sawdust they leave behind. Termites also differ from carpenter ants by being thicker and lighter in colour, as well as having straight antennae. Finally, carpenter ants build their colonies by burrowing into wood and digging tunnels much longer than those created by termites. If you open up a piece of wood that you think has been infested, look at the size of the galleries to determine which insect has taken up residence. 

What attracts carpenter ants to a house? 

Food and easy access usually. Carpenter ants prefer to burrow through soft wood (like pine). They also prefer wood that has been damaged by moisture or fungus because it’s easier to penetrate. If your house has water damage in an attic or roof, they might be tempted to enter if food is scarce outside or if there is a nest close by. Worker ants get sent on scouting missions to find food for the colony and can also gain entrance through doors, windows, and chimneys. 

Can carpenter ants cause structural damage? 

These pests can cause significant damage to not only wooden support beams but also hollow doors and foam insulation. Over time, as they expand their nests, they can cause structures to warp or even collapse. While it takes years for them to cause significant damage, they often go unnoticed until it’s an expensive fix. 

Since carpenter ants prefer moist, rotting wood, their presence could indicate a larger issue related to moisture, such as a leaky roof or poor ventilation. On their own, these pests are unlikely to cause your home to collapse; however, they can weaken supports and a foundation enough for heavy inclement weather to do the rest.

How do I find a carpenter ant nest in my house? 

The sooner you catch them, the less damage they can do to the joists, support beams, trusses, and foundation. If you haven’t had your home checked by a pest control professional, don’t worry! Carpenter ants are easy to locate and don’t go out of their way to hide themselves. They tend to be active in the evening, so that’s the best time to look for them. Here’s what to look for: 

• Small holes in wood panelling or unexplained piles of sawdust. Carpenter ants hollow out the wood they burrow through, so if you knock on something that should be solid and hear an echo, you may have found a colony. 
• Damp areas, including wood around holes that can be accessed from outside. Check sinks (carpenter ants can home in on dirty dishes) and showers as well as appliance hookups and patio doors. If you find holes where there shouldn’t be any, you may have found an entry point. 
• Entry points that touch the ground, like doors and windows with plants or trees growing near them. Ants like to follow established paths so once they have a route, they’ll keep using it unless they find a compelling reason not to. 
• Rustling noises. Carpenter ants communicate by making this kind of noise, often when they are disturbed or if something is close to a nest. Tap your walls to see if there are hollow areas. If you get rustling in response, chances are you have either found a colony or are close to one.
• The ants themselves. Since they don’t eat wood, they have to find food elsewhere and will often come out when it’s darker and cooler. They eat other insects, small invertebrates (like spiders and worms), proteins, and sweets. While carpenter ants tend to enjoy aphids out in the wild (because of the sticky sap the smaller bugs excrete), they will cheerfully raid snack cupboards and cookie jars that are not sealed securely. 
• Piles of dead ants, insect pieces, or tiny wings. Carpenter ants shed their wings when mating season is over. They discard what they can’t eat by throwing it out of the colony at an entry point. 
• Swarming ants. If you catch them during mating time, they will have wings and cluster. If you find an ant swarm outside of your house (such as near a woodpile or dead tree), count yourself lucky and take steps to do away with them. 

While humans don’t hibernate in winter, ants do if they don’t have access to a heat source. If you go looking for a colony in winter, search for locations that are warm or that allow heat to collect, like crawlspaces or vents.

How do I get rid of carpenter ants in my home? 

There are two ways to go about removing carpenter ants from your home: doing it yourself or hiring an expert.  

DIY carpenter ant removal 

If you plan on doing it yourself, be sure that you’ve located the colony as it can take a couple of weeks before you know for certain that the ants are gone. 

Here are some DIY options you can try: 

• Sweets and baking soda. If you find a nest, you should be able to clear it by baiting the ants with a 1:1 mixture of something sweet (e.g., sugar, jam) and baking soda in a shallow dish. Leave it where they can find it – the sugar will lure them, and the baking soda will kill them. 

• Dish soap and water. Mix a simple 1:2 solution of dish soap and water and clean your home as usual. 
• Essential oils. If you like wiping down surfaces, essential oils blended with a carrier oil can get the job done. 
• Vinegar and water. A 1:1 combination of these household items is another natural and strong ant repellent. 

Try to avoid using pesticides, simply because poisons intended for insects can also hurt pets or family members. For instance, a favoured pesticide called pyrethrin is extracted from chrysanthemums and kills carpenter ants on contact. However, refined pyrethrin is toxic to aquatic creatures and can cause allergic reactions in people, especially folks with asthma.

Hire a decontamination expert 

If hunting for ant colonies and testing your luck with DIY methods isn’t your cup of tea, you can always call in the professionals. Decontamination experts can locate and effectively remove carpenter ant nests without causing further damage to your home, loved ones, or pets. They’ll also get the job done right the first time, so you don’t have to worry about another infestation. 

A place for ants and ants in their place 

Like most living things, ants are useful in the natural world. They get rid of remains that larger creatures won’t touch, break down wood and other remnants, and serve as a treat for smaller mammals who like their protein in bite-sized portions. That said, they can also be destructive, undermining the stability of a house or building. When in doubt, reach out to a licensed professional: they can help you determine the right course of action. 

Looking for advice on other home decontamination projects? Check out our blog posts and learn about the risks of vermiculite, how to prevent humidity in crawl spaces, and how to remove mould in your home.

By Anthony Granziol

Anthony Granziol is a freelance writer and academic editor who is interested in words, how people communicate, and why we say what we say. His bachelor’s degree in English and SSW diploma have given him a unique insight on helping people and the world we share. He has written for businesses, schools, nonprofits, and even himself. When he isn’t burrowing into articles, books, blogs, or essays, you can find him going for walks with his son, cooking for his family, or teasing text to make it leaner, clearer, and more expressive while keeping its intent just so.