Are Carpenter Ants Dangerous?

Carpenter ants are a type of pest easily mistaken for termites because of their wood-boring behaviors. A larger species of ant, they burrow into wooden structures, similar to termites, and can cause damage to property in a similar way to termites. Here’s what you need to know about the kind of effects a carpenter ant infestation can have on your home.

Carpenter Ant Behaviors

As their name suggests, carpenter ants build their homes in wood, digging smooth-sided tunnels in order to maneuver and find food. Unlike termites, carpenter ants do not eat wood—they simply chew it with their mandibles and discard it as waste. One of the largest species of ants, these pests are also the most problematic because of how much structural damage they can wreak. 

Carpenter ants usually reach about ⅝ inch in length, and are red, black, brown, or a combination of the two. Like other ants, they have segmented bodies. The main indicator of their presence is the holes they create in wood when burrowing.

Carpenter ants need a water source to survive, which is one reason why the primary kind of wood they target is dead, rotting, or damp. It’s easier to dig into and provides them with a source of moisture. Outdoors, they may be found creating nests in tree stumps, fence posts, firewood, or landscaping. Indoors, they may be found digging into damaged windows and door frames, crawlspaces, attics, chimneys, sinks, bathtubs, and old wooden siding.

Since carpenter ants are larger insects, the damage they create may be more obvious and more destructive. They regularly leave their nests to forage and return to continue digging. If you find small but obvious holes in wood on your property that appear to be tunnels, especially if it looks like a small pile of sawdust is collecting under them, you may have discovered a carpenter ant infestation.

How Carpenter Ants Infest Homes

Carpenter ants often enter homes through holes or gaps in the walls. They can use low-hanging tree branches, electrical wires, mulch, and firewood piles as highways indoors, and start making trouble without you even noticing their presence. While carpenter ants do prefer to dig in moist, rotting wood, they aren’t necessarily picky, and may begin to infest your home whether or not the wooden parts of your home are old or rotting. It’s a good idea to keep an eye on wooden parts of your home like exposed support beams, railings, and decorative trim to ensure that they aren’t being compromised by carpenter ants.

Carpenter ants have more tolerance for the outdoor elements than termites do, which makes it easier for them to get around and find new wooden structures to burrow into. Often, a carpenter ant infestation will begin outdoors in a main nest in a tree or fence, then move indoors if they find a weak spot. Carpenter ant colonies can often contain more than 10,000 workers with multiple “satellite” colonies with a home. This can mean bad news for your home’s structural integrity and value.

These pests may also find a way into your home when they swarm. In warm weather, if a colony has grown to max capacity, a carpenter ant colony will send out winged ants to form new colonies. If these swarmers find soft, rotting, or vulnerable wood on your property or in your home, they may begin to build new nests.

To avoid a carpenter ant infestation, keep an eye on the wood on or near your home and make sure it stays in good condition, replacing and repairing it as needed. Also, keep wood piles at least 20 feet away from your home and five inches off the ground. Then, find any holes or crevices on the outside of your home and seal them with caulk.