Of all the types of pest problems you can have, wood damage is probably the worst. Insects that damage wood like carpenter ants and termites are a homeowners worst nightmare. They can cause thousands of dollars in property damage if left unchecked.
While they aren’t quite as devastating as termites, carpenter ants can cause significant damage to the wood in your home by burrowing through it. Unlike termites, they do not eat wood. Instead, they tunnel through it to make their nests inside of damp wood in your home. Signs of a carpenter ant infestation are often hidden until serious damage has been done.
I’m here to give you our best DIY advice on how to get rid of carpenter ants. This guide will tell you how to identifying carpenter ants, kill their nests, and ensure they don’t come back.
How to Identify Carpenter Ants
One tough thing about carpenter ants is that there are a lot of species – 24 in the United States alone. Their size and color can vary tremendously, even within a species (for example, winged male drones are significantly larger than the workers who damage your home). That said, the most common species of carpenter ant in the home is the black carpenter ant (Camponotus pennsylvanicus), which is (obviously) shiny and black in color.
Though their color can vary, all carpenter ants share some important details in their body shape. First, carpenter ants have only one bump (node) on their waist between the thorax and abdomen. They also have a curved back to their thorax, a heart-shaped head, and elbowed antennae.
Carpenter ants are also some of the largest ants. Workers are up to 12mm in length. Size is not always a reliable identifier though, since worker size can vary within a colony.
If you’re struggling to tell if an ant you’ve seen is a carpenter ant, try capturing it and putting it in the freezer to kill it. It’ll be much easier to identify these small characteristics once it’s not moving.
4 Step Guide to Getting Rid of Carpenter Ants
Step 1: Do You Have Carpenter Ants?
The first step of treating any pest problem is to identify what exactly you’re up against. There are many good signs that you have carpenter ants.
Because most carpenter ants are huge and black, they aren’t too hard to spot. If you see even a single carpenter ant in your home, you should be on alert. Multiple ants are a pretty good sign you have an infestation. If you see large winged males, it’s almost certain you have an infestation. These winged males emerge when colonies reproduce and are unlikely to live long enough to make it into your home from the outside.
Signs of Carpenter Ant Damage
Carpenter ant damage can be hard to spot because they tend to tunnel within wood rather than make a lot of damage on the surface. It is possible to spot the signs of damage, though.
You may see piles of wood shavings or sawdust around baseboards, door jams, or windowsills. This is because the ants don’t actually consume the wood, they just tunnel through it and toss the sawdust out an entrance. They may also toss bits of insulation and insect body parts out of their tunnels amongst the sawdust.
You may be able to see these tunnels in your woodwork, but they are often hidden from the outside. Though you may not be able to see them, you can sometimes hear carpenter ants rustling around from within the woodwork.
If you do see wood that has very smooth carvings in it, that’s usually the work of carpenter ants. Termites are much less sophisticated.
Looking for Carpenter Ant Nests
Carpenter ants are attracted to old, rotting wood, so their primary nest is often outside the home in an old stump, a pile of firewood, or other debris. If you believe you may have carpenter ants, check any old stumps or wood around your home first. If you don’t find the colony there, you may have an unaddressed structural problem in your home (e.g. a leak) that could be creating moisture and wet wood that attracts these ants. Finding their main nest will save you a lot of headaches later on.
Carpenter Ants versus Termites
Carpenter ants and termites are easily confused since they both cause wood damage, but they are quite different. You definitely want to correctly identify your infestation in your home, because a termite infestation is usually a much bigger problem than carpenter ants.
Ants and termites are in different orders of insects and thus have very different body shapes. Ants have very tapered waists, while termites are squatter. Termites also have straight antennae, whereas ants have bent ones. When they have wings, ant wings are much shorter than termite wings relative to their body.
The damage caused by these two insects also looks different. Carpenter ants are much neater with the tunnels they make. They will be polished and smooth. Termite tunnels are rough, ragged, and full of soil and dirt.
Carpenter Ants versus Black House Ants
Carpenter ants are much larger than regular black house ants, so that’s a good place to start when trying to tell the difference. You can also refer to some of the body characteristics in the previous section for carpenter ants.
It’s a good idea to try to capture an ant to identify it because these two ant problems have a very different prognosis. Carpenter ants damage your home, but black house ants are usually just looking for food. They can be annoying, but don’t cause much harm in the long run and will usually go away if you follow our guide to getting rid of house ants.
Step 2: Attack the Colony
Once you know you have carpenter ants, it’s time to go on the offensive! The good news is that unlike termites, carpenter ants can often be handled without professional help. There are two main ways to kill carpenter ants.
First is baiting, which is the process of using toxic bait to attract the ants, who collect the bait and share it with the rest of the colony. The other method is spraying pesticides. The newer sprays on the market are non-repellent, which means that the ants aren’t driven away by the smell and it makes it a lot easier to get them to spread the toxic chemicals among the rest of the colony. These are definitely superior to intense, repellent sprays of the past.
In most cases, the carpenter ants are using your home as a satellite colony with the main colony being somewhere outside. The most important thing about baiting is making sure the bait ends up on the path between your home and their parent colony.
Bait around the perimeter of your home, as well as around the base of trees, piles of firewood, or stumps. It’s better to use too much bait than too little, so apply it around any sources of damp wood where the ants may be hiding. If you are lucky enough to be able to identify the specific path the ants are using between the nest and your house, bait heavily there as well.
There are two types of bait – protein-based baits, and sugar-based baits. It’s important to use a combination of baits, since insects may pick up different baits depending on their food needs at the time. One of the best sugar-based baits is Advion Ant Bait Gel.
Its active ingredient, indoxacarb, is a unique chemical that spreads more easily between insects because it has been scientifically proven to spread to both secondary and tertiary targets. This means that if an ant picks up a bit of Advion bait, it will spread the toxin to its neighbors, and those ants will in turn spread it to their neighbors. This makes it much more efficient in killing a whole colony than other baits.
A good choice for a protein-based bait is Advance Carpenter Ant Bait. It doesn’t have the same active ingredient as the Advion, so it might not have the same incredible spreading power, but it’s a good backup for when the ants are in the mood for some protein.
For best results and severe infestations, baiting both inside and outside is the best strategy. However, you can also just bait outside if you want to keep the bait out of your house, which is a good idea if you have pets or small children. In general, you should always at least bait outside though.
You can also apply sprays around the exterior of your home and around any suspected ant colonies and trails. Sprays are a good complement to baiting, but only when non-repellent sprays are used. While these sprays are more expensive than other pesticides, their killing power makes them very much worth the price when dealing with carpenter ants.
One good non-repellent spray for carpenter ants is Termidor SC. Termidor works on many insects, including termites and carpenter ants, but should only be used outdoors.
The interesting thing about Termidor is that it sticks around. The USDA has found that Termidor still kills insects on concrete slabs and ground boards 7 whole years after the initial application! This means once you’ve treated once, you won’t have to again for years.
Phantom is another good spray product. It’s quite potent, but the residual does not last as long as Termidor (only about 30 days). It’s also virtually undetectable to insects (hence the name). Unlike Termidor, Phantom can be used indoors in cracks and crevices around your home. For this reason, it’s a better choice than Termidor if you believe you have a sizeable nest in your home.
No matter what spray you use, make sure to use a non-repellent spray like those above. Sprays that repel insects will kill some ants but will not kill the whole colony because any ants not in the immediate vicinity of the spray will not go near the chemicals. Non-repellent sprays can be used right along with baits and will encourage the insects to go about their day and spread the insecticide around before finally dying.
Step 3: Spray for Residual Ants
Back in step 2 if you only baited and didn’t use any sort of spray, now is the time to add one in. Baits are great for knocking down the colony, but you’ll still have straggler ants that weren’t killed. By applying a pesticide spray, you’ll help protect your home against reinfestations. I suggest using one of the sprays recommended above for exterior home treatment.
You’ll want to spray around the foundation of your home, following the label’s instructions for carpenter ants. Most will recommend something like 2 feet up the foundation’s exterior and 2 feet of the ground around your home. You may also want to spray any wet or rotting wood around your house, too.
For inside, you can spray a foaming product like Fuse Foam directly into the ant tunnels to get any last hard-to-reach ants. This product will foam up inside the tunnel, allowing it to spread and reach much further inside than any liquid could ever hope to. It eventually dissipates and leaves the pesticide behind.
Step 4: Prevent Carpenter Ants from Returning
Carpenter ants are often preventable because their behavior is predictable. They usually end up in homes because they’ve made a large colony somewhere nearby, so you can keep them out of your home by making sure they can’t find a good place to nest on your property.
Carpenter ants like damp wood. So make sure to clear things like old rotting woodpiles and dead stumps from your yard. Ants also love damp wood within your home, so fix up any issues with your plumbing or roofing that could be causing leaks. Moisture issues can attract a wide range of pests, not just carpenter ants!
You should also seal any cracks and crevices in and around your home since these are great places for ants to enter. Keeping brush trimmed back away from the house is also a good idea to give ants fewer things to crawl on close to your home.
You can also spray your foundation regularly with a product like Phantom or Termidor to kill nosey ants. Like most insects, carpenter ants activity varies with the season. They start becoming active in the spring, so this is a good time to spray.
Carpenter Ant FAQ’s
How do I find the carpenter ants’ nest?
This is the hardest part of dealing with carpenter ants. Sometimes it takes very dedicated searching! There are two kinds of nest – parent colonies and satellite colonies. Most parent colonies are found outside the home in damp wood. They are often found in hardwood trees with holes, cracks, or other imperfections. Indoors, they tend to make their nests in moisture-damaged wood. So bathrooms, kitchens, and basements are a great place to start looking.
One strategy for looking for nests in wood is to try to knock on the wood. A hollow sound is a good sign of damaged wood, and sometimes knocking causes the ants to panic and scatter from the nest, which is a good way to confirm they are there!
Do carpenter ants eat wood?
No! They do damage wood, but they don’t actually consume it. They just shave it away. That’s one of the ways to recognize carpenter ant damage versus termite damage. Carpenter ants leave behind little piles of shavings and sawdust, but termites just gobble it all up.
Do carpenter ants bite?
They can occasionally bite when they feel threatened, but they don’t do it often. You’d have to work pretty hard to bother a carpenter ant enough for it to bite you.
Where in the US are carpenter ants most common?
Because they like cool, damp wood, carpenter ants are much more common in the northern parts of the United States. You are less likely to find them in hot desert states like Arizona or New Mexico.
Can carpenter ants kill a tree?
Carpenter ants usually take advantage of a tree that’s already damaged by age, disease, or moisture. They won’t infest a thriving, healthy tree. A particularly bad infestation may push a damaged tree over the edge, but I wouldn’t’ worry about any of the young, healthy trees in your yard. See how to get rid of carpenter ants in a tree.
Do carpenter ants fly?
Yes, but only the males. This is true of ants in general. Flying ants are a part of the swarming cycle, which is when ants leave the nest to make new colonies. If you see flying carpenter ants in your home, this is a certain sign that you have a major ant problem.
Does mulch attract carpenter ants?
There’s some differing opinion about this, but I’d be inclined to say no. Mulch doesn’t really have a lot to offer a carpenter ant since they like wet, rotting wood and they use it to make their nest. A pile of old, rotting mulch may attract carpenter ants, but they aren’t likely to get a lot of joy out of digging into your freshly mulched flowerbeds.