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Carpenter Ants


What Do Carpenter Ants Look Like?

Carpenter Ant

  • Commonly black, ranging in hues from red to yellow
  • Up to 1 inch or 25 millimetres long (workers can be 3 to 13 mm), nearly 5 times the size of a typical pavement ant or black garden ant.
  • a single small segment between the thorax and abdomen
  • Upper side of the thorax is smooth and round

Known to nest in wooden structures, carpenter ants are common pests to invade homes in Canada. Typically earth toned carpenter ants range from reddish brown to dull black depending on species. Like any ant, the carpenter ant’s body consists of a head, thorax, and abdomen. The head includes a set of large mandibles that open horizontally like scissors and a pair of antennae that take an elbow shape. Six legs attach to the thorax, and a narrow petiole (waist) separates the thorax from the abdomen. A carpenter ant’s abdomen, or gaster, is bulbous and covered in long, yellowish hairs this is only true for the black carpenter ant. (Should include here the node, the number of nodes, smooth rounded thorax and the circle of hair at tip of abdomen, these are the outstanding ID for carpenter ants

The most effective way to identify a carpenter ant is by looking at the petiole and the thorax. A carpenter ant’s petiole has one node, which makes the area between the thorax and abdomen look like a small notch. Other worker ants that can be mistaken for carpenter ants have two-node petioles. Additionally, the thorax of the carpenter ant is evenly rounded, whereas other ant species have a bumpy thorax. Properly identifying a carpenter ant can be difficult without close inspection.

carpenter ant image

Carpenter ants are some of the largest ants in North America. Workers, the caste that can usually be seen in the home, average between 6.5 and 13 mm in length. Though known for being large, carpenter ants are difficult to identify by size alone because the length of workers varies by species. Additionally, worker sizes may fluctuate within a species and even within a colony.

Swarms of winged carpenter ants can be seen outdoors during summer months. Often mistaken for termites, winged carpenter ants are distinguishable by narrow waists, elbowed antennae, and front wings that are longer than hind wings. Winged female carpenter ants are usually larger than worker carpenter ants and may measure between 20 and 25 mm long.

More Carpenter Ant Images


Why should I be concerned?

Carpenter ants love to chew through the wood used in constructing homes and other buildings. In order to build their galleries, carpenter ants will hollow out decorative and structural material. Although they work slowly, if left alone or untreated, they can cause severe Carpenter Ants in the Homedamage requiring costly repairs or replacement. It is always better to treat and prevent at the first signs of an infestation. If you spot large carpenter ants, with or without wings, it is a sign of an established colony and you need to call your local pest control professional.

Do Carpenter Ants Bite Humans?

Renowned excavators, carpenter ants use their powerful jaws to loosen and remove wood debris when tunneling or building nests. Carpenter ants do not have stings therefore they do not sting people. However, they use their formidable mandibles to defend their nests when attacked. Carpenter ants rarely bite humans; the powerful jaws of a worker can bite and tear through human skin; the bite inflicted is sprayed with formic acid which gives a burning sensation. Reaction to carpenter ants bites various from individual to individual; which in most cases is mild. While occurrences of carpenter ants biting people prove rare, cases do exist in which humans have sustained bites..

Habitat and Behaviour

A day in the life of carpenter ants

It is easy to admire the carpenter ants dedication to cleanliness. Unlike termite, which pack mud and debris into the hollowed wood, carpenter ants will thoroughly clean their galleries and nesting sites. Near the entrances to a colony, you may find “frass” which is a sawdust like material containing wood, insect parts, or excrements which has been carried out of their nest.

Since they prefer moist wood, you are most likely to encounter carpenter ants on or near around or under decks, porches, windows, roofs, and other exposed areas which are exposed to the weather. The ideal location will provide protection from predators and the weather as well as easy access to sources of food.

Life Cycle

Carpenter Ant Queen

The carpenter ant queen is a fertilized, functional female of the colony. She is wingless, about 13 -25 mm long, colour is dependent on species but often range from dark brown, reddish, yellow, or black tones. Similar in appearance to worker ants, the queen’s body is divided into a head, thorax, and abdomen, or gaster. The queen is solely responsible for producing offspring and the keeping the colony together. Most carpenter ant species have one functional queen per colony; however some species have multiple queens.

Colonies and Larvae

Nest building and colony formation begins when after mating with a male, a fertilized winged females lands, sheds off her wings and finds a suitable nesting location, which is usually in decaying wood of hollow trees or logs, including manmade wood structures, which causes damage to the property. Once a suitable nest location is found, the queen lays first batch of eggs (15 – 20). She feeds and tends to the larvae which eventually develop into sterile workers that take over all nest-building duties. While workers forage for food, excavate the nest, and care for young carpenter ants, the queen concentrates on egg production. Egg production usually doubles following the first brood. Once the nest is mature, the carpenter ant queen lays eggs that develop into reproductively capable males and females. A nest often takes several years to mature and usually needs about 3,000 workers before the queen begins a new reproduction cycle.

Do Carpenter Ants Fly?

Like other ant species found in Canada, carpenter ants are social insects that live in large colonies formed of three castes; workers, males and queens. The most common carpenter ants encountered in the home are the workers and are wingless foragers of food. Worker ants cannot fly. As the name suggests workers ants exist to work. They build and repair the nest, feed and defend the colony, and care for the queen and her brood. Carpenter ant queens form the highest caste. The founding functional queen is wingless and does not fly. Carpenter ant colonies produce winged male and female reproductives that emerge and swarm during the spring or early summer, they mate during such nuptial flights. Mated females land, shed off their wings and locate a suitable site to start new colonies, meanwhile the males die.


What Do Carpenter Ants Eat?

Carpenter ants are predators that will feed on other insects, both alive and dead. Their diet also includes a range of plant nectars and juices, honeydew, syrup, jelly, sugar, salt, fruits, meat, grease, and fat. These are guests you don’t want to invite to your barbecue!

The common name of the carpenter ant refers to the excavating abilities of the insect rather than the diet of the pest. When carpenter ants excavate tunnels from wooden structures, the destructive insects merely chew on the wood and then discard the shavings, which pile up like sawdust beneath the entrance hole of the nest. In the natural environment outdoors, carpenter ants eat small insects and other invertebrates, plant juices, and the sweet honeydew secreted by aphids. Worker ants are responsible for supplying the entire carpenter ant colony with enough food and must leave the nest regularly to forage.

When searching for food, carpenter ants may forage in areas as far as 100 yards away from the nest. They use pheromones to mark their foraging trails. The great distances traveled by foraging carpenter ants often puts the pest insects in direct contact with the homes of Canadian residents. Carpenter ants enter homes and other buildings through cracks and other openings in the foundation or via tree branches abutting the roof. Once inside, foraging ants search for and take from a variety of food sources. Because carpenter ants feed on proteins as well as carbohydrates, the omnivorous insects raid kitchens for meats, sugar, and syrupy ingredients like honey and jelly. Carpenter ants are also drawn to the grease spills and pet food commonly found in many homes throughout Canada.

Tips for prevention and control

These tips may help you prevent carpenter ants in your home:

  • Food debris and crumbs will attract ants indoors
  • Wood debris should be removed from around the house
  • Wood piles should be moved away from structures
  • Overhanging trees should be pruned or trimmed so that they are not in contact with the structure
  • Gutters and downspouts should be clean and free flowing

Test Your Knowledge of Carpenter Ants


    1. What do carpenter ants eat?
      1. Wood
      2. Plant nectars
      3. Other Insects
      4. Pet Food
      5. B, C and D
    2. True or false. If you spot carpenter ants, it could be a sign of a nearby established colony.


    1. E. Carpenter ants are known to chew through the wood used in constructing homes and other buildings, but they don’t actually eat it. In order to build their galleries, carpenter ants will hollow out decorative and structural material.
    2. True. You should call your local Orkin Man, because without treatment, carpenter ants can inflict severe structural damage, requiring costly repairs.

Carpenter Ants in the Home

Carpenter Ant Damage

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