Carpenter Ant Behavior and Types

Get rid of carpenter ants by understanding carpenter ant types and behavior.

Do you have the larger Black carpenter Ant or the smaller, reddish Florida carpenter ant? Identification and inspection would be different for each one of these types. Once you identify and inspect, you can get rid of these carpenter ants with success.

carpenter ants eating wood
Black Carpenter Ants
black carpenter ant
Black Carpenter Ant
(Univ. of Nebraska)

Black Carpenter Ants

Eastern United States: (Camponotus pennsylvanicus)

  • Color: All black Workers: 1/4–1/2-inch in size
  • Queen: Large, over 1/2-inch in size
  • Swarming: Colony matures in 3–4 years, swarming occurs in late spring–summer
  • Distribution: Mid West to Eastern States

Western United States (Camponotus modoc) (Camponotus vicinus)

  • Color: Black Body, red dark legs
  • Workers: 1/5–1/2-inch in size, but variable Queen: Large, over 1/2-inch in size
  • Swarming: Occurs in late spring–summer.
  • Colony size: Up to 15,000 workers
  • Distribution: Western US States Nests: Generally excavates in decayed or damaged wood. Creates smooth tunnels and galleries.They can compromise structural integrity by expanding into sound wood. Nests may be found in dead trees and stumps outside.
Florida carpenter ants
Florida Carpenter Ant
Florida carpenter ants
Florida Carpenter Ants

Florida Carpenter Ants

Eastern United States: (Cabdominalis floridanus))

  • Color:Red head, black abdomen, thorax, and legs Workers: Smaller, 3/16–3/8-inches in size
  • Queen: Large, over 1/2-inch in size
  • Unmated swarmers in satellite colonies
  • Distribution: Florida and southeast U.S.
  • Colony Size:Up to 3,500 workers.
  • Nests:Seeks to nest in existing voids or excavates soft woods that are rotten and styrofoam.
Field Ant
Field Ant (Univ of Nebraska)

Field Ants (Not to be confused with the Carpenter Ant)

The Field Ant (Formica) may be identified as a carpenter ant and are found throughout the USA. Both carpenter ants and field ants have one node or a one-segmented waist. The field ants have an uneven thorax, and the carpenter ants have an evenly rounded thorax.

Field ants may come inside to forage but do not establish nests inside like the carpenter ant. They nest in soil or decayed logs and construct their nest from grass stems, twigs, pine needles, etc., forming a mound.

They form low-profile mounds in the yard. Their mounds can reach a foot or more in diameter. If the mound is disturbed, they may aggressively swarm out and bite the intruder. The bite may sting. During the fall months, they are commonly noticed as they swarm from underground to new locations to establish new colonies. Use an ant bait granular around the mound like Maxforce Complete Ant Bait.

Carpenter Ant Diet

Outdoors, carpenter ants feed on protein-based foods (such as living and dead insects) and sweet-based foods (such as the honeydew produced by aphids and certain scale insects). Indoors, carpenter ants feed on meat and fats, and any sweet food such as syrups and jellies.

Carpenter Ant Habits

Carpenter ants are nocturnal. They prefer to hollow out their nests in softened wood, such as moist or partially decayed wood. Their nests are called galleries. These galleries are clean and have a sandpaper appearance.

In comparison, termite galleries are rough-looking. Wood that has been damaged by carpenter ants contain no mud-like material, as is the case with termites.

Florida Carpenter Ant nests are commonly found indoors in such places as the moist, hollow wall void behind dishwashers. Nests are usually found in areas where water leakage could occur, such as around bathtubs, sinks, roof leaks, poorly-flashed chimneys, or poorly sealed windows or door frames. Outdoor nests are found in places like tree stumps, hollow logs, fence posts, or dead portions of standing trees. However, these persistent creatures have even been known to build nests in cracks and crevices of sound wood.

Carpenter ants may establish nests in several different locations. It is important to understand that you can have both inside and outside nests. Carpenter ants construct two different kinds of nests: parent and satellite colonies. Parent colonies, when mature, contain an egg-laying queen, a brood, and 2,000 or more worker Ants. Satellite colonies may have large numbers of worker ants but contain no queen, eggs, or larvae. For example, the ants found in your home may have originated from parent nests outdoors, perhaps in a tree stump, timber, or woodpile, or from one or more satellite nests hidden behind a wall in the kitchen or bathroom, or perhaps from wood dampened by a roof leak in the attic. Although large carpenter ant colonies can cause structural damage,
the damage is not normally as serious as termite damage.

Often, the ants you see inside your home are simply foraging for food, and you may not see large numbers of them. Foraging workers can travel 100 yards from nest to food and can be found wandering throughout your house.

Key Takeaway

Carpenter ant food gathering workers are most active just after dark.

Carpenter Ant Control Product Recommendations

Various Ants That Invade Homes and Businesses

Written by our resident pest control expert Ken Martin.