Carpenter Ant


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.

Fast Facts

Color Most commonly black, but can also be black and red.
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 – 1/2″ in length, while the winged reproductives and queens are usually about 3/4″ long.
Appearance 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.


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, 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.


Outdoors, they 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. Carpenter ants remain active during warmer weather and hibernate during winter, but if they are indoors, they can remain active year-round.

Colonies & Life Cycle

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. The vast majority of carpenter ants in the colony are workers. Worker carpenter ants can vary in size between 1/8-1/2″ in length. The workers have a number of duties, including feeding the queen and larvae and defending 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. Larger than the average carpenter ant, swarmers are 3/4″ in size. If you spot carpenter ant swarmers, it may be an indication that a colony is located nearby.

Damage & Signs of Infestation

The most serious problem caused by carpenter ants is the damage they inflict on wood. During the process of building a nest, carpenter ants excavate the springwood found between the rings of hardwood 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 depends on the number of nests and the longevity of the colony.


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. If you see any more than 20 ants emerging from baseboards, window casings or vents in spring or summer, it may indicate the presence of a large colony.


Signs of activity include piles of wood shavings the ants discard during excavation and the rustling noises produced by their activity in walls and ceilings.

Damaged Wood

Carpenter ants tunnel through wood to create their nests, creating ‘galleries’ in wood, which have a clean, smooth and sandpapered appearance.


If you hear a crunching sound it could be the sound of rustling from their nests in the wood of your home. Nests are usually built-in wood structures and can also be found in wall or ceiling voids.

Prevention & Control

Carpenter Ant Prevention

To prevent a carpenter ant infestation, steps must be taken to discourage the pests from entering the home in the first place.

  • Leaks: Repair plumbing leaks around the house, and replace any moist or rotting timber with undamaged, treated wood.
  • Moisture: Keep damp areas properly ventilated to prevent moisture from accumulating and turning formerly dry wood into prime nesting sites for carpenter ants.
  • Tree and Branch Maintenance: Prevent tree branches from touching the outside of the home to help restrict access to the structure. Remove nearby rotting or dead trees in your backyard – these often provide ideal conditions for a carpenter ant nest and a good base from which they can explore the area closer or even inside your home. Carpenter ants are known to travel great distances for food.
  • Drainage: Make sure the grade of the ground allows water to flow away from the building and refrain from putting mulch directly against the foundation.
  • Wood Storage: Storing firewood in a dry place away from the house may also reduce the chances of an infestation. An infestation in a woodpile can quickly become an infestation in a home.
Carpenter Ant Control

Batzner Pest Control recommends the following carpenter ant control methods depending on the specific nature of your infestation.

  • Dust Material Treatments: A very effective treatment method for carpenter ants indoors; pesticide dust materials both flush out hidden ant nests and remove the carpenter ants.
  • Nest & Barrier Treatments: The most common method of treatment for carpenter ants is the treatment of nests and barriers with residual insecticides.
  • Perimeter Treatments: In addition to applying a treatment to any carpenter ant nests/barriers, a treatment is applied to the perimeter of your home with a liquid residual material.
  • Year-Round Pest Control: Regular inspections of your home by a pest control professional throughout the year is the best method to identify and prevent any issues with carpenter ants or any other pests.