DAMAGE
Carpenter ants do not eat wood, and generally are not as damaging as termites. Carpenter ants use narrow, protected void areas for nests and may be found in doors, window frames, and walls. Southern carpenter ant species prefer to nest in existing voids and cavities and do not usually excavate large nests in wood. For this reason, and because they tend to have smaller colonies, Texas carpenter ants are not as destructive as species found in the northwest and northeastern regions of the United States. At worst, carpenter ants may, on occasion, cause minor damage to isolated pieces of wood. Because carpenter ants are classified as wood-destroying insects, however, they are reportable on real estate transactions and can affect the resale value of a home.

CONTROL
Carpenter ant control can be difficult. The surest way to eliminate a carpenter ant infestation is to locate and treat the nest, or nests. Carpenter ants make their homes in a variety of sites including solid wood, hollow core doors, window and door frames, hollow walls, insulation, cardboard boxes, etc. Although carpenter ants can bore into sound, dry wood, they prefer using existing cavities or excavating softer materials, especially near a moisture source.

Carpenter ant nests can sometimes be located by the presence of small piles of sawdust, or frass. This frass consists of wood shavings or other material excavated from the ant's nests, as well as tiny fragments of dead ants and other insects. The presence of frass is a good sign that a nest is nearby. Carpenter ant frass is usually pushed out of a small hole in the nest chamber. If you can find such a hole, it frequently leads directly into the nest chamber.

Should you attempt carpenter ant control yourself? Although do-it-yourself drilling and treating walls is possible, an easier approach is the use of baits. Carpenter ants have traditionally been difficult to lure with baits, however some new products may be worth trying. Whitmire Granular Carpenter Ant Bait, Maxforce® Carpenter Ant Gel, and Maxforce® Outdoor Ant Killer Granules have been used successfully against carpenter ants. These products should be placed outdoors along carpenter ant foraging trails. Containerized ant baits often include label recommendations for indoor use against carpenter ants, however they have had little reported success against our Texas species. Commercial boric acid baits using peanut butter, molasses or jelly as an attractant may control some colonies. Baits with lower percentages of boric acid (1-2%) appear to work best. Fire ant baits are unattractive to carpenter ants.

Baits should be placed near ant trails or wherever carpenter ants are seen. The best way to locate outdoor foraging trails is to use a flashlight at night in warm weather, when the ants are most active. Trails will be found along fences or tree branches, wires, etc. Once picked up by ants, baits are transported to the colony where they are shared with the queen and other ants. If one bait seems unattractive when first offered, try it again in another month. Carpenter ants go through seasonal changes in their food preferences-- preferring sweets at times, and proteins at other times. Do not use other pesticides near sites where you are baiting, as this may repel the ants.

FOR MORE INFORMATION
For more information on carpenter ants and their control, request publication L-1783, Carpenter Ants, or L-2061 House-Infesting Ants and their Management.

Author:
Michael Merchant, Ph.D., Urban Entomologist, Texas Agricultural Extension Service

Publication information:
This publication is part of the House & Landscape Pest Series produced by the Department of Entomology, Texas A&M University, College Station, TX 77843-2475. Series Editor: M. Merchant. For more information about arthropods, check out the Texas A&M Entomology Website at http://insects.tamu.edu/
Last Revised: 06/26/2003