Identifying characteristics

• Workers are all the same size, small, 1/8-inch long
• Dark brown to shiny black
• Petiole with 1 node, hidden by abdomen
• Thorax uneven in shape when viewed from side
• Very strong odor when crushed

Feed on both dead and living insects, favoring aphid and scale honeydew  In homes, forage primarily for sweets Travel in both wandering patterns and set trails Trails common along branches of trees, foundations, sidewalks, baseboards, and edges of carpets When disturbed, become erratic with their abdomens raised in the air Nest type and size Live in shallow nests in soil under stones, wood, or debris May nest in various habitats including wooded areas, beaches, wall voids, and around water pipes and heaters Large colonies, with up to 10,000 workers and many queens

Carpenter ants are large (¼–1 in) ants indigenous to many parts of the world. They prefer dead, damp wood in which to build nests. Sometimes carpenter ants will hollow out sections of trees. The most likely species to be infesting a house in the United States is the Black carpenter ant, Camponotus pennsylvanicus. However, there are over a thousand other species in the genus Camponotus.

Symbionts
All ants in this genus, and also some related genera, possess an obligate bacterial endosymbiont called Blochmannia.[1] This bacterium has a small genome, and retains genes to biosynthesize essential amino acids and other nutrients. This suggests the bacterium plays a role in ant nutrition. Many Camponotus species are also infected with Wolbachia, another endosymbiont that is widespread across insect groups.

Habitat
Carpenter ant species reside both outdoors and indoors in moist, decaying or hollow wood. They cut "galleries" into the wood grain to provide passageways for movement from section to section of the nest.

As Pests
Carpenter ants can damage wood used in the construction of buildings. They can leave a sawdust like material behind that provides clues to nesting location.

Exploding ants
In at least nine Southeast Asian species of the Cylindricus complex, such as Camponotus saundersi, workers feature greatly enlarged mandibular glands. They can release their contents suicidally by rupturing the intersegmental membrane of the gaster, resulting in a spray of toxic substance from the head, which gave these species the common name "exploding ants"
Its defensive behaviors include self-destruction by autothysis. Two oversized, poison-filled mandibular glands run the entire length of the ant's body. When combat takes a turn for the worse, the ant violently contracts its abdominal muscles to rupture its body and spray poison or glue in all directions.[3][4] The ant has an enormously enlarged mandibular (abdomen) gland, many times the size of a normal ant, which produces the glue. The glue bursts out and entangles and immobilizes all nearby victims.
The termite, Globitermes sulphureus has a similar defensive mechanism.