Carpenter Ants

Carpenter Ant Control: Protect Your Home


Scientific Classification: Camponotus spp.

Class Order Family
Insecta Hymenoptera Formicidae


Carpenter ants are pests that nest in wood. Outdoors, the insects live in hollow trees, logs and stumps, where they facilitate the breakdown of dead or decaying wood and prey on other pests. However, carpenter ants often enter indoor areas to look for food or nesting sites. In fact, the potentially destructive insects rank among the most common pest species of ants in the Mid-Atlantic and other northern regions. Named for their habit of excavating nests out of wood, carpenter ants cause property damage when they tunnel through the frameworks and timbers of homes.


carpenter ant closeup
Carpenter Ant

What Do They Look Like?

Size: Larger than other common ant species, carpenter ants vary in size depending on their role within the colony. Worker ants typically measure between 1/8 and 1/2 inches (3.5-13 mm) in length, while the winged reproductives and queens are usually about 3/4 inches (19 mm) long.

Color: Carpenter ants generally range in color from black to brown or red. The most common Mid-Atlantic species is the black carpenter ant, while other species found in the region boast a combination of dark and reddish colors. In the western United States, the most frequently occurring species of carpenter ant is dull black in color with reddish legs and golden hairs on the abdomen.

Characteristics: Often mistaken for termites, carpenter ants differ from their wood-boring counterparts by having elbowed antennae and a constricted waist that connects the thorax with the abdomen. Workers are polymorphic, which means they encompass a wide range of sizes. Carpenter ant queens have large front wings.

Geographic Range

Together, the nine species of carpenter ants found in the United States cover the entire country. The pests tend to inhabit regions with cool, damp climates most commonly. Black carpenter ants live in the eastern part of the country while the western carpenter ant populates the West Coast and Rocky Mountain areas.


What Do They Eat?

In their natural environment outdoors, carpenter ants primarily feed on the sugary honeydew that aphids and similar insects secrete. The omnivores also consume plant saps and dead or live insects. When they forage for food indoors, carpenter ants tend to prefer sweets, proteins and fats. The pests feed on common household items such as fruit, honey, jam, meat, grease and crumbs of bread. Foraging carpenter ants follow a regular trail that can be traced back to the nest.


During late spring and early summer, mature carpenter ant colonies of at least 2,000 members produce winged reproductives called swarmers that emerge from the old nest and leave to mate and establish new colonies. After mating, the male dies while the newly fertilized queen locates a suitable piece of wood, excavates a nest and lays between 15 and 20 eggs. The first generation of offspring hatches in about two months and takes another three months to develop into adults. Carpenter ants reach adulthood only after completing the larval and pupal stages of the life cycle.

As adults, the older generations of worker ants forage for food, maintain the nest and care for the future generations of offspring produced by the queen whose sole responsibility is to lay eggs. Once the colony matures and becomes large enough, swarmers emerge to begin the mating process anew. Carpenter ants remain active during warmer weather and hibernate during winter although inside, they can remain active year round.


  • Look for nests in moist or decaying wood near plumbing leaks, window sills, porch pillars, wall voids, bathtubs and showers, leaky appliances and similar locations.
  • Listen for the rustling sounds of active carpenter ants in the walls.
  • Look for piles of sawdust-like shavings discarded by excavating carpenter ants and sometimes mixed with the debris of insulation and dead insects.
  • Watch for foraging trails in the basement, attic, garage and outside, especially between the hours of 10:00 p.m. and 2:00 a.m. during the summer. Be on the lookout for winged swarmers during the early part of the spring.

Problems Caused by Carpenter Ants

Carpenter ants steal food and damage property. When the pests invade homes, they establish foraging trails and feed on various household foods. The more serious problem caused by carpenter ants, however, is the damage they inflict on wood. During the process of building a nest, carpenter ants excavate the spring wood found between the rings of hard wood in timbers. Although the pests mainly attack moist or damaged wood, they can excavate structurally sound wood as well. The level of damage caused by carpenter ants generally varies according to the number of nests in the building and the longevity of the colony.

Signs of Infestation

While the presence of foraging workers indicates the existence of a nearby infestation, the nest itself could either be inside the building or somewhere outdoors. A stronger sign of a carpenter ant infestation is the presence of winged reproductives or swarmers inside the home which means the nest is probably also indoors. Other signs of infestation include the piles of wood shavings the pests discard during excavation and the rustling noises produced by their activity in walls and ceilings.

Prevention Tips

To prevent a carpenter ant infestation, steps must be taken to discourage the pests from entering the home in the first place. Repair plumbing leaks around the house, and replace any moist or rotting timber with undamaged, treated wood. Keep damp areas properly ventilated to prevent moisture from accumulating and turning formerly dry wood into prime nesting sites for carpenter ants. Preventing tree branches from touching the outside of the home can help restrict access to the structure, while storing firewood in a dry place away from the house may also reduce the chances of an infestation. Make sure the grade of the ground allows water to flow away from the building, and refrain from putting mulch directly against the foundation.

Tips for Removal from Home

Removing carpenter ants from the home can be a challenging undertaking. These pests prefer honeydew secreted from aphids found outside during the season as opposed to baits. Targeted insecticidal treatments typically resolve infestations quickly. Furthermore, in addition to the main colony carpenter ants often establish multiple satellite nests within the same area. Complete control can only occur when all the nests are located and treated. Pest management professionals know how to find carpenter ant nests and have the most effective tools for eliminating the pests completely. If a carpenter ant infestation occurs, count on a professional pest management service to take care of the problem knowledgeably and successfully.

Carpenter Ant Control that Prevents Damage

In the role nature intended for them, carpenter ants break down rotting wood and leave behind richly fertilized soil. However, in our homes the only thing they leave behind is crumbling walls and expensive repair work. Carpenter ants can reduce solid structures to hollow shells but unlike termites, they don’t do so by eating and digesting wood. Instead, they burrow through it creating networks of tunnels and leaving behind piles of sawdust in their quest to feast on the preferred protein and sugar meals found in most homes. The presence of carpenter ants in your home is serious business-they are difficult to eradicate and in most cases will require the services of a professional pest service to control and prevent further ant infestations. The longer carpenter ants reside in and around your home, the larger their network of nests will be and the greater damage they will cause to your home.

Found in moist or decaying wood, carpenter ants cut galleries into wood to create passageways and nesting sites, and they can ultimately impact the stability of wooden structures if left untreated. At their largest, carpenter ants can be up to an inch long, and at the first sighting it’s wise to take action.

Carpenter ants are wood-boring insects that excavate wood through smooth, precise tunnels that they use for nests. Once they’ve made their home inside your home, it is difficult to eradicate the problem

What’s the best way to get rid of the problem?

  • Find moisture sources: Conditions conducive to water buildup can attract ants and many other pests as well.
  • Move wood piles: Wood or wood-based products should be stored at least a foot away from the home. An infestation in a wood pile can quickly become an infestation in a home.
  • Mind your mulch: “Mulch looks great, but it’s a harborage for many insects,” Presti says.

Carpenter ants get their name from their habit of hollowing out wood to make their nests. The ants do not eat the wood, but they can cause considerable damage with their tunneling.

Carpenter ants are very large ants. There are different sized workers in a colony of carpenter ants. The smallest workers are about 1/8″ long. The very largest workers in the colony can reach almost 1/2″ long. The queens are usually a little larger than the largest workers.

Read more about what a carpenter ant looks like.

Carpenter ants belong to the ant family Formicidae and the genus Camponotus. There are several species of carpenter ants in the U.S. Some of the most common carpenter ant species are:

• Camponotus pennsylvanicus (DeGeer) This ant is completely black. Its abdomen is covered with yellow hairs. It is common throughout the eastern U.S.

• Camponotus modoc (Wheeler) This ant has a black body and red legs. There are yellow hairs on the abdomen. This ant is common throughout the western states. Camponotus vicinus (Mayr) is common in Washington State. It is red and black.

• Camponotus novaboracensis (Fitch) This ant is known as the red carpenter ant. It is common in the northern states and is found westward to Minnesota and North Dakota.

• Camponotus floridanus (Buckley) This ant has a dark abdomen with a red head and mid-section. It is common throughout the southeast from North Carolina to Mississippi. The Camponotus tortuganus (Emery) is a black carpenter ant that is found along the Gulf coast.

• Camponotus variegates (Fr. Smith) This ant is found in Hawaii. It has also been found in Washington State. It is yellowish brown in color.

• Camponotus acutirostris (Wheeler) This ant is found in West Texas, New Mexico, and Arizona.

Carpenter ant workers move about in trails. They are usually active at night and on cloudy days. They gather insects and honeydew to feed the colony. The workers move into homes to find food or water. They often make a satellite nest inside the home. Homeowners often find the workers moving in line from the kitchen or bathroom taking food or water to the main colony outside.

If there is wood that is wet or that has decayed, the carpenter ants often find it and hollow it out for their nest. Because of this preference for decayed wood, homeowners find carpenter ants nesting in eaves, roof decking, siding, bath traps, window frames, and other places where water can cause wood to decay. Carpenter ants often nest in wood that has been damaged by termites. The ants eat the termites and nest in the termite galleries.

Carpenter ants also nest in the foam sheathing that homebuilders use in home construction. Homeowners find small pieces of foam on the ground outside beside the foundation.

Preventing carpenter ants begins outdoors. Move firewood away from the house. Trim tree limbs and shrubs that touch the house. Make sure exterior doors close tightly and caulk any cracks around doors and windows. Repair screens on windows and vents.