This month's "bug"

bug of the month pictureCommon scorpionfly


Recently featured "bugs"

News picture Common green darner



news pictureCandy-striped leafhopper


Bug of the Month: Black carpenter ant

Common name: Black carpenter ant

Latin name: Camponotus pennsylvanicus (De Geer) 1773

Kingdom Animalia
   Phylum Arthropoda
      Class Insecta
         Order Hymenoptera
            Family Formicidae


Front image of head of a black carpenter ant
Ants in general

Ants are familiar insects to most people. This is because they are extremely abundant, and they often occur in habitats also occupied by humans. Over 12,000 species of ants have been identified worldwide, and around 700 species live in North America. Ants are important members of almost any ecosystem, as predators, seed dispersers, soil aerators, and nutrient recyclers. Ants are social insects and live in large colonies. At most times of the year, all ants in the colony are wingless females, but only the queen can produce eggs (the other females are sterile). When a nest gets too crowded—usually in the spring—new winged ants, males and young queens, fly out of the nest and mate, ultimately creating new ant colonies. Ants are found world-wide, except in the very coldest places, and on the most remote islands. Many ant species have been introduced to new places by humans and they have become very successful colonizers. Currently, we have documented 36 species of ants on the Boston Harbor Islands.

How to identify black carpenter ants

Like all ants, carpenter ants (Camponotus) have 3 main body parts, the head, the mesosoma (thorax plus first abdominal segment), and the gaster (the last segments of the abdomen). In between the mesosoma and gaster is the petiole, which, in carpenter ants, is made up of a single node. The mesosoma of all carpenter ants has a smooth, arched outline on the top. Black carpenter ants can be identified by their large size (0.5 to 1.5 cm), all black body color, and the presence of long, stiff light-colored hairs on the gaster.

side view of black carpenter ant

Where to find black carpenter ants on the Boston Harbor Islands

Carpenter ants can be found in and around rotting wood. However, foraging ants can be found wandering all over the place, especially near forests or potential food sources.

How black carpenter ants make a living

Carpenter ants get their name because they usually carve tunnels and passages through dead wood (e.g., tree snags or stumps) to make burrows for their colonies. They can even be found chewing their way though human-built wooden structures like houses or porches if the wood is moist and has begun to rot. Even though black carpenter ants live and burrow in wood, they can't digest it. They are omnivores, which means that they eat both animals and plants. They have been known to hunt other insects (even other carpenter ants!), forage from dead animals, and harvest and eat things like fruits, vegetables, and tubers.

overhead view of a black carpenter antWhere in the world black carpenter ants occur

Carpenter ants are found all over the world. Though only four species have been found on the Boston Harbor islands to date, there are several more that are native to the northeastern United States. Camponotus pennsylvanicus, in particular, is a common species in the eastern United States.

To learn more about black carpenter ants (and ants in general)

On the web:

In print:

    Agosti, D. Ants: Standard methods for measuring and monitoring biodiversity. Smithsonian Press. Washington D.C.

    Fisher, B. L. and Cover, S. P. 2007. Ants of North America : A Guide to the Genera. University of California Press. Berkely, CA.

    Hölldobler, B. and E. O. Wilson. 1990. The ants. Belknap Press of Harvard University Press. Cambridge, MA.