These long-legged, swiftly-moving creatures are among our largest ants which may occasionally invade
homes foraging for food or for nest building. The workers are highly polymorphic, that is they vary greatly
in size ranging from 1/4 inch to more than 3/8 inch. The queens may be more than 1/2 inch long. The
black carpenter ant, Camponotus pennsylvanicus, is the most common carpenter ant in the eastern states.
It is a dull black color with an abdomen covered with long yellowish hairs pressed against the body
surface. Foraging workers may be from 1/4 to 1/2 inch or more in length. Other common eastern species
include the red carpenter ant, C. ferrugineus, and the Florida carpenter ant, C. abdominalis. Although
found in much of the eastern United States, C. rasilis, is probably one of the most common species
encountered in the Gulf Coast states. Its head, thorax and petiole are reddish and the gaster is black.
Worker size varies from 4 to 9 mm long. A species found throughout the United States is C. nearcticus,
which is smaller with the workers being 4.5 to 7.5 mm long.
Carpenter ants, because of their large size and biting ability, attract more than a passing glance from even
the neophyte nature lover. It is a common experience of hikers, who seek the comfort of a woodland log,
to find themselves suddenly beset by large numbers of these biting ants. Carpenter ants are distributed
widely throughout the United States and range from sea level to well above 9,000 feet in the western
mountain ranges. They very often are pests in lawns as well as homes. Since theirs is the habit of dwelling
in and excavating wood, they were given the common name of “carpenter ant.”
The colony is ordinarily initiated by one queen, who begins the nest beneath a rock or in the soil, or in an
insect-bored tunnel in a tree, etc. The queen lays only a few eggs and these hatch into very small workers.
The minims or small workers then go forth to forage. The small workers then feed the young and the
queen, whose sole interest in life is the production of eggs. If the enviroment is propitious, the colony
thrives. The pupae are closed in cocoons, which are referred to by most individuals as “ant eggs.” When
the nesting site is in wood, it often resembles an ornate carving due to the multiplicity of the galleries.
These galleries are so smooth, they appear to have been sandpapered. The carpenter ants ordinarily
excavate that portion of the wood softened by decay or by the attacks of other insects. However, Fowler
(1986) stated that carpenter ants are more often found in sound wood than rotten wood.
Pricer (1908) made a detailed study of the life history of the black carpenter ant in Illinois at a temperature
of 70 to 90 degrees F. The female laid 22 eggs in 15 days. The eggs stage took 24 days, larval stage 21
days and pupal stage 21 days (66 days from egg to adult). Under natural conditions, the larval stage may
be of much longer duration during the winter. The winged sexual forms were observed to emerge about
the first of July. Large colonies may be characterized by winged males and females during the winter. The
colony does not produce the winged forms until it is more than two years old. These winged sexuals,
which may be produced during one summer, overwinter in the parental nest and emerge for their marriage
flight from May to July. One colony had as many as 3,212 worker ants.