Skip Navigation

University of Nebraska–Lincoln

UNL Extension in Lancaster County

Insects, Spiders, Mice & More

Carpenter Ant Identification

Resources to help you identify carpenter ants found in Nebraska .

Return to:

Carpenter Ant Queen

Helping Nebraskans enhance their lives through research-based education.

Carpenter Ant Identification (One Node Ant)


Carpenter Ants (Camponotus, spp.)

Black Carpenter Ant

Above: Camponotus pennsylvanicus

Below: Camponotus sayi

Red Carpenter Ant

Camponotus pennsylvanicus

Black Carpenter Ant Actual SizeDescription of Workers: Medium to large workers, 1/4-inch to 1/2-inch. Thorax evenly rounded. Colonies have workers that are not all the same size (polymorphism). Black carpenter ants are most common species in Nebraska.

Camponotus sayi

Red Carpenter AntDescription of Workers: Workers of a second carpenter ant species, C. sayi have reddish-brown head and thorax and black abdomen. It is unofficially called the "red" carpenter ant to distinguish it from the black species. These ants are about 3/16-inch to 1/4-inch long.

Habits:


Both species of Carpenter ants nest in wood and are often associated with moisture problems. In structures, they are often found where water has leaked and soaked the surrounding wood, around plumbing, under windows, in soffits, where the roof has leaked.

Contrary to popular belief these ants DO NOT eat wood. The diet of carpenter ants includes living and dead insects, honeydew from aphids, sweets, meat, and fats.

Carpenter ants use their strong mouthparts to tunnel wood to make galleries. This resulting sawdust looks like fine wood shavings, but is not powdery. It may contain foam insulation.

Workers of C. pennsylvanicus (black carpenter ants) can travel 300 ft from colonies so carpenter ants inside do not necessarily mean there is a colony within the structure.

Carpenter ants are most active at night, emerging after dusk and returning to their colony prior to dawn. Some foraging occurs during the day. Carpenter ants make noise that sound like crinkling cellophane as they move about in their colony. A stethoscope may be helpful in finding colonies within a wall.

Management:


Management involves eliminating moisture problems associated with interior colonies to correct conditions suitable for colony survival. Treatment involves locating and appropriately treating colonies. Insecticidal dusts are often used in wall voids because liquid insecticides soak into wood and may not spread throughout wall voids so ants will track the dust back to the colony. It may be desirable to hire a pest control professional who has appropriate equipment and expertise to treat wall voids. Colonies can sometimes be eliminated by discarding infested wood or by vacuuming ants. In these situations, no insecticides may be needed.

View Carpenter Ant Photos and Damage - UNL Department of Entomology



The information on this Web site is valid for residents of southeastern Nebraska. It may or may not apply in your area. If you live outside southeastern Nebraska, visit your local Extension office

Credits: Ant illustrations were developed by Vicki Jedlicka, University of Nebraska-Lincoln Extension in Lancaster County

For information on reproducing this resource or using any photographs or graphics, read the Terms of Use statement)

Return for More ResourcesReturn to Ant Identification Resources