A carpenter ant infestation in your home can cause your skin to crawl, but it can also lead to sleepless nights and structural damage. These big black ants don’t sting or pose any real threat to humans, but they are destructive when they get inside your home.
This article will tell you everything you need to know to get rid of carpenter ants. It will cover how you can identify these ants, what kind of damage they can do, how to eliminate an infestation, and how to prevent them from coming back.
Most people know carpenter ants as those huge ants that chew through tree stumps and logs, leaving behind a mess of holes and wood shavings.
There are several species of carpenter ant, but something they all share is their size: they're some of the biggest ants in the United States. Depending on the ant’s caste (its role in the colony) and its sex, a carpenter ant can range in size from a quarter-inch to an inch long.
In North America, the most common types of carpenter ants are black and red carpenter ants. The black ones are the big black ants, and the red ones have a reddish-brown thorax (the middle section of the body).
Aside from their coloring and size, you can also identify carpenter ants by their long, thin thorax and their bent antennae. And depending on the species, carpenter ants might also have long hairs on their abdomens. That’s the part of the body that’s farthest from the head. As for their heads, these are heart-shaped.
Finally, some carpenter ants have wings. After the breeding males and females mate, the males fly off to die, and the females go out to establish new colonies. If you’ve seen a large winged ant in your house or garden, then it could have been a carpenter ant.
Carpenter ants don’t actually eat wood. Rather, they use wood to build their homes and nesting sites. They chew into the wood to create networks of tunnels and galleries where they create nests, lay eggs, and raise their young.
Carpenter ants prefer damp wood or wood that has otherwise been softened from things like rot or other insects. You'll often find carpenter ants in logs, tree stumps, wooden structures like beams and posts, standing trees that are dead or alive, stacks of firewood, and other types of wood.
Inside your house, you're most likely to find carpenter ants making nests in wood that has been water damaged. That can include wood:
Having carpenter ants in the garden isn't generally a problem for plants or the garden itself. They don’t typically harm healthy trees, but they will take advantage of an injured or unhealthy tree. The main thing you have to worry about is that a carpenter ant colony on your property may send out a satellite colony that ends up inside your house.
An untreated carpenter ant infestation inside can cause structural damage. Carpenter ants will eat into anything wood, including framing, joists, beams, studs, trusses, and other structurally important components. Carpenter ants can also destroy furniture, cabinetry, shelving, and other non-structural wooden items around the house.
What's more, because carpenter ants love wood that’s been softened by moisture or rot, they can cause more damage to structures that have already been compromised.
You can minimize the damage by finding and eliminating an infestation early. It can take anywhere from three to six years for a colony to establish itself, but it’s still important to act quickly. If carpenter ants aren't removed fast enough, the colony can grow and spread, creating even more damage.
As carpenter ants chew out their tunnels and galleries, they expel sawdust and wood shavings from the nest. This can leave debris around your house, especially near entrances to the nest.
Finally, a carpenter ant infestation can lead to sleepless nights because they make noise as they gnaw on the wood and smooth out their tunnels. The sound isn't too loud, but it can be very disruptive, particularly if you live somewhere quiet or have sensitive ears.
Carpenter ants do bite, but they don’t do it very often. When they do, it’s usually in self-defense.
These ants don’t have stingers or venom, but you may experience redness and some pain or a burning sensation if you're bitten. The wound won’t likely need any special treatment, but you can wash it with soap and water to help prevent infection.
The first and most obvious sign of a carpenter ant infestation is seeing one of these big black ants in your house or garden. However, one ant doesn’t necessarily mean a colony has made a nest nearby—these little creatures have been known to travel up to 100 yards in search of food.
If you suspect you have an infestation, here are some signs you can look for:
Carpenter ants seek out nest sites where they have access to what they need to survive.
Namely, they need soft or damp wood, water, and food. One of the most important things is damp wood because this is what carpenter ants need to build a nest.
Inside your home, there are lots of circumstances that could create the perfect conditions for them. For example, if you’ve had leaky pipes, your home is too humid, there's a crack in the roof, or one of the windows leaks, then water could have softened some of the wood in the house.
As for food, carpenter ants eat invertebrates and honeydew, a sugar-rich nectar produced by aphids and some other insects. But if carpenter ants find sugary foods or protein in your house, then they’ll eat that as well.
When carpenter ants can't find the right kind of wood, a water source, or a food source in your house or garden, they won’t stick around to establish a colony.
1. Find the nest.
A carpenter ant colony usually has at least 3,000 ants, and the first thing you have to do is find where they're hiding. Here are some tips that can help:
One of the easiest ways to locate the nest will be to follow the ants. Any time you find an ant in the house or garden, follow it until it gets to the hole that leads to the nest.
2. Use bait to bring out the ants.
You can lure the ants out using bait if you have trouble locating the nest. Carpenter ants love sweet things like sugar and honey. Leave small amounts of these sweet treats around the house or garden and watch the traps. When you catch the ants in action, you can follow them back to their holes.
3. Destroy the nest.
Once you have a good idea of where the ants have built their nest, you can eliminate it.
For outdoor nests, you may be able to take apart the rotting wood the ants are using and move it away from your property in pieces. Wear protective gloves and long sleeves to avoid bites.
For nests that are inside, one of the most popular methods is chemical treatment. Because the nest is probably behind a wall or in some other inaccessible place, you may need to drill small holes that will enable the chemical to get in and do its job. There are a few products you can use, such as:
Always read and follow the label carefully when you're using insecticides and chemical treatments, especially if you have children or pets in the house.
Depending on how accessible the nest is, you may be able to suck up the ants with a vacuum cleaner instead of using a chemical treatment.
4. Call a Professional Pest Control Company for Stubborn Infestations.
Not everyone wants to drill holes in the walls and use insecticide in the house. Plus, it’s possible that these methods still won’t eliminate the colony. In those cases, your best bet may be to call a professional to do the job and make sure the colony is destroyed.
A pest company will also determine if the infestation is a satellite nest. If that’s the case, then there may be a parent colony nearby that needs to be eliminated as well.
5. Clean the house.
Carpenter ants use scent trails made of pheromones to navigate to their nests. After the nest has been destroyed, clean the house to remove the scent trails that any stragglers might use to find their way back home.
Clean and wash floors, window sills, baseboards, walls, and other surfaces where the ants may have left a pheromone trail. You can use a household cleaner or a homemade mixture like water and vinegar.
6. Fix Any Structural Damage the Ants Caused.
An established carpenter ant colony can cause a lot of damage to the wood in your home. If the colony has been there for a while, you may need to replace some structural woodwork, such as framing, joists, floorboards, posts, beams, or studs.
Whether you’ve recently dealt with a carpenter ant infestation or just want to avoid one, there are several things you can do around the house and on your property to deter carpenter ants from setting up shop.
Outside, remove possible nesting sites, including rotting logs, fallen trees, old stumps, sick trees, fallen branches, and firewood. This is especially important right around the house. The ants could easily migrate inside if their nest is already close to the house.
Along with removing wood from around the property, you should also replace rotting or wet wood throughout the house. This is especially important if you’ve already had a problem with carpenter ants because it probably means there’s moist wood somewhere in the house.
Check around sinks, tubs, showers, water-using appliances like dishwashers, and other plumbing for potential leaks, and make sure the wood around them is sound. Replace any wood that’s been damaged or compromised by moisture.
Water-damaged wood can be tricky because you can't always see the problem. Dipping and warping are both signs of water damage in wood floors, even if the wood appears intact. Look for mold as well, which indicates the presence of moisture.
Carpenter ants will also nest in wood that’s been previously damaged by other insects, such as termites, so you'll need to replace insect-damaged wood too.
It’s also a good idea to remove standing water that could create the ideal conditions for a nesting site. Remember, carpenter ants love damp wood, so keep your property dry, inside and out. Here are some ideas of how water can create issues on the property:
Carpenter ants are more than capable of finding food in the wild, but they’ll still be attracted to sweet things and protein they can find readily in your house.
Store food properly to discourage carpenter ants. That means keeping food in sealed containers, refrigerating leftovers promptly, cleaning up spills when they happen, and sweeping or vacuuming regularly to keep crumbs to a minimum.
And here's one more tip: take steps to remove other insects from your home that could make an easy feast for carpenter ants. Keeping your home clean is a good first step, but you may also have to treat house plants for aphids and other insects that ants find tasty.
Carpenter ants always need a way to get into your house. Sometimes, they’ll burrow into the walls from the outside. Other times, they’ll find an access point, like a crack, and get in that way.
Ants can squeeze in through very tiny holes, so here are some ideas of where you can look for potential entry points:
High moisture levels in your house can cause water damage to wood structures over time, and the problem can be more widespread compared to the damage caused by a single leaky pipe.
Some thermostats have humidity sensors, but you can also buy a hygrometer to test the humidity in your home. Room dehumidifiers or whole-home systems are both great options to eliminate excess moisture in the house.
Another potential problem could be groundwater seeping into your basement or crawlspace. In that case, you can install moisture barriers to prevent water from getting in.
A carpenter ant colony in your garden might not be a big deal, but a nest in your house can disrupt your sleep, leave a mess, and cause damage to structural components.
To get rid of carpenter ants, the first thing you have to do is find the nest. Once you’ve done that, you can eliminate it with insecticide or other chemicals. Outdoors, you can remove a nest by breaking apart the structure and moving it away from your property. When the nest is gone, you'll have to clean up the scent trails, fix any damage the ants caused, and take steps to prevent another infestation.
When in doubt, you can always call a professional pest control company to assess the situation and destroy the nest permanently.