Two black carpenter ants (Camponotus pennsylvanicus) engage in trophallaxis. Photo courtesy of, and copyrighted by, Gene White, pmimages@earthlink.net

Camponotus spp.

Alias: Carpenter ant

Description

• The nest galleries some carpenter ant species cut into wood generally are smooth and clean, which is how they earned the “carpenter” moniker.
• Workers of invasive carpenter species vary in size, among the smallest being those of C. nearcticus, which are 3/16 to 1/4 of an inch long.
• Carpenter ants seen indoors are mostly black; however, some species, such as C. vicinus, C. chromaiodes, and C. floridanus have reddish body sections and/or leg segments.
• Polymorphic workers for the larger species vary in size, from 1/4- to 3/4-inch long.

Life Cycle

• The queen is present in the primary nest, which is located away from the home or infested structure.
• No egg-laying queen is present in the secondary, or satellite nests, which are located within the structure.
• More than one satellite nest may be associated with different primary nests, and therefore, separate colonies.
• Each colony typically has only one egg-laying queen.
• For most colonies, alates, or winged reproductives, form in three to six years, at which time about 2,500 or more individuals will be present.
• Populations within colonies vary; some include more than 100,000 individuals.
• Alates may be produced any time of the year, but usually develop in late summer.

Behavior

• Although some carpenter ant species (Camponotus modoc and C. pennsylvanicus) excavate cavities in structural wood and foamboard (EPS) insulation, most structure-invading species are opportunistic nesters, occupying existing cavities/gaps in exterior walls, roofing, and interior features.
• They often excavate tunnels and galleries in structural wood that already is in a state of decay due to retained moisture.
• They do not use wood for food.
• They establish nests in many different outdoor situations, such as tree trunks and branches, stumps, logs, landscaping timbers, fenceposts and sometimes in covered soil.
• Indoor nests may be found in windowsills, hollow doors, roofs, porch substructures, baseboards, fireplaces, shingles or other naturally hollow areas. A hollow pipe may even serve as a nest.
• Nesting activities may weaken building structures, but not as seriously as termites.
• In wooded areas, many colonies may be present around an infested home.
• Carpenter ants often move into a building solely to scavenge and feed.
• They may be carried into homes in firewood, or enter and establish colonies via other routes.
• Foragers can enter homes via tree limbs or wires that touch the house; thus the nest may or may not be inside the home.

Food

• Foraging ants will travel 100 yards or more from the nest for food.
• During warm months, they will forage most actively in early nighttime hours.
• Carpenter ants feed on a variety of animal and plant foods, and will feed on other living or dead insects.
• They will feed on nearly anything people eat, including sweets. Aphid honeydew is especially appealing.

Range ➔ Various species are widespread throughout the United States.

Prevention ➔ Eliminate moisture and water sources; remove food sources by keeping food sealed; prune shrubs and trees so they do not touch the structure; seal entry points into structures; store firewood and lumber away from the home.

SOURCE: Truman’s Scientific Guide to Pest Management Operations