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The Carpenter Ant

Winged Ants in Your Home


The Carpenter Ant
photo by Richard Bartz

There are many species of carpenter ants, varying primarily by geography. However all carpenter ants nest in wood and can cause damage to the wood of homes, buildings and structures.

Although carpenter ants are one of the largest ant species in the U.S. size is not necessarily a determining factor in the identification of carpenter ants, because the different castes and sexes are often of different sizes.

For example:

  • Workers range from 1/4 to 5/8 inch in length and are the most commonly seen.
  • Males are about the same size as the workers, but are generally only seen when they fly from the nest to mate with the queen - their only purpose in life.
  • The queen is the largest of the species, and may be two or three times larger than the workers.

Carpenter Ant Facts

Carpenter ants:

  • are one of most common species of ants in the U.S.
  • vary in color as in size, but are generally reddish orange to black.
  • do not eat the wood in which they nest, but chew into it with their excessively large mandibles, as they create galleries and connecting tunnels.
  • nest outdoors in dead and decaying wood, such as hollow and rotting trees, old stumps, and even firewood.
  • nest in homes and buildings, in enclosed areas where the wood is damp, wet or otherwise decayed. If infestations grow, they may also expand into sound wood, and they have also been found in foam insulation.
  • usually have more than one nesting site, including a parent and satellite colonies.
  • damage structures through the excavation of their extensive galleries and tunnels and nesting in areas such as wall voids, hollow doors, and insulation.
  • feed on proteins and sugars, such as honeydew produced by aphids; meats; and sweets such as syrup, honey, and jelly.
  • may forage in the home for food; will do so primarily at night in the spring and summer.
  • can't sting but can inflict painful bites with their powerful jaws and spray formic acid into the wound, causing a burning sensation. (Source: University of California)

How to know if you have an infestation

You may have an infestation:

  • if you have seen the ants in your home or building during the late fall, winter and early spring. However, one or two in the spring or summer does not necessarily indicate a problem.

  • if you are seeing flying ants emerging from your home in the spring time. (Note: these may also be termites. See How to Tell the Difference)

  • if you have wet or spongy wood, such as around leaky pipes, drains, walls or roofing, and you are seeing ants or evidence of their presence in the area.

Carpenter Ant Control

You can control carpenter ants with chemical or bait treatments (See Control Carpenter Ants for more information).

However the most effective and lasting form of control is replacement of wet and damaged wood in which the carpenter ants are nesting and repair of conditions causing the damage - such as roofing or plumbing leaks or other moisture issues. Then to help prevent future infestation, eliminate direct contact of soil, plants and mulch with the structure. For example, trim trees and shrubs away from the home or building, keep any wood from contacting soil, seal cracks and openings in the found, and store firewood well away from the home.

If the infestation seems to be extensive, or you are having difficulty finding or eradicating the ants - or you just don't want to do it yourself, contact a professional, keeping in mind the Top 12 Considerations in Hiring a Pest Control Professional.

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