How to Identify and Get Rid of Carpenter Ants

Carpenter ants are large ants native to many parts of the world that can cause major structural damage to homes. Identifying an infestation and getting rid of these pests as soon as possible is important to prevent continued damage. Here is a detailed guide on how to identify and get rid of carpenter ants.

Signs of a Carpenter Ant Infestation

Here are some of the most common signs that will alert you to a carpenter ant problem:

  • Sawdust-like material called “frass” found near wood. Carpenter ants excavate wood to create galleries and leave behind this sawdust-like material. Seeing piles of it near windows, doors, or along the foundation is a telltale sign.
  • Hollow sounding wood. Tapping on wood that has been tunneled through by carpenter ants will have a hollow sound. This is a good way to pinpoint their activity.
  • Large ants seen swarming in the spring. Carpenter ants are one of the largest ants found in homes, around 1/4-1/2 inch long. Seeing large ants flying around or crawling in the house in spring indicates an established colony.
  • Small piles of dead wings. After swarming, carpenter ants will shed their wings. Finding small piles of discarded wings around the house means a colony is nearby.
  • Slowly expanding stain on wood. The excavated tunnels may cause wood to darken, creating a slowly spreading stain over time. This happens when the damaged wood absorbs light differently.

If you suspect an infestation, inspect your home carefully for any signs of ants, sawdust, or damage. Attics, roofs, decks, and untreated outdoor wood are common nesting spots.

How to Get Rid of Carpenter Ants

Getting rid of carpenter ants requires finding and directly treating the nest. Here are the most effective methods:

Apply Pesticide Spray in and Around the Nest

Liquid or dust insecticides applied directly into carpenter ant nests will kill them faster than traps or baits. Spray inside detected nesting areas and around trails in the house. This helps quickly knock down ants. Reapply regularly as needed.

Use Ant Baits

Ant baits containing slow-acting toxins carried back to the nest and shared amongst the colony can provide control. Place small bait stations along trails and potential nest sites. It may take a few weeks to fully eliminate ants.

Inject Pesticides into Infested Wood

For existing nests inside wood, directly injecting pesticides into the galleries provides the best penetration. This targets ants deep inside. You can also apply dusts into nest openings. Consult a professional exterminator for treatment of nests inside structures.

Make Your Home Less Inviting

Trimming trees and vegetation touching the house, sealing cracks, fixing leaks, and ensuring proper drainage away from the structure removes conditions ants look for in a nest site. This helps prevent future infestations.

Call a Professional Exterminator

For large, established nests inside the home’s structure, calling a professional pest control company is advised. They have the expertise and insecticides needed to fully eliminate and prevent future colonies. This provides the most thorough treatment.

FAQs About Identifying and Getting Rid of Carpenter Ants

What do carpenter ants look like?

Carpenter ants have large, polymorphic workers ranging from 1/4 inch to 1/2 inch long. They are black or red and black in color. They have a thorax with even rounded lobes and an abdomen with fine, dense hairs. Carpenter ants look noticeably different from termites.

Where do carpenter ants nest?

Outdoors, carpenter ants nest in dead trees, stumps, logs, and wooden landscaping material. Indoors, they nest in wet, damaged, or hollow sections of wooden structures. Common areas include roofs, walls, attics, and around windows or doors.

Do carpenter ants eat wood?

No, carpenter ants do not actually eat wood like termites. They excavate dry, moist wood to create smooth galleries and tunnels for their nests. They keep the tunnels very clean and push out any wood debris.

What should I do if there are carpenter ants in my house?

If you see carpenter ants inside, inspect for nest locations and immediately treat them with insecticide spray or dust. Seal any holes where they enter. Remove any excess wood debris. Work to make your home less hospitable to future colonies. Consider calling an exterminator if infestation is advanced.

How do you kill carpenter ants naturally?

Some natural options to kill and repel carpenter ants include using diatomaceous earth, sprinkling boric acid powder along trails, spraying ants directly with vinegar, using essential oils like peppermint or tea tree, or placing sliced garlic or lemon peel near entry points.

When do carpenter ants swarm?

Carpenter ants swarm and establish new colonies in early spring, typically March to May depending on climate. Existing colonies also produce winged reproductive ants around this time that go on mating flights and shed their wings after landing.


Carpenter ants can certainly cause frustration and damage if left unchecked. Keep an eye out for the telltale signs of an infestation. Combining proper insecticide treatment directly in nesting sites, ant baits, and making your home less welcoming to ants will provide the best defense. With early intervention and diligence, you can send those carpenter ants packing.