Aspects of the behavior, biology, and economic importance of carpenter ants were examined. The overall objectives of this study were to determine the economic importance of carpenter ants, and to extend the data currently available on two of the most common and economically important species in the U.S.

A survey for the economic importance of carpenter ants indicated that carpenter ants are considered a serious pest by homeowners. The results show that 90% of the homeowners who requested control for carpenter ants during 1980, paid more than $25 for carpenter ant control. The presence of detectable damage was not the definitive factor in the decision to request control.

Camponotus ferrugineus and C. pennsylvanicus are similar in their colony foundation and biology. C. ferrugineus required 54 days to produce the first brood and there were 18 workers, including one intermediate worker, in the first brood. Queens of C. pennsylvanicus required an average of 46 days to rear the first brood. Ad libitum feeding did not have a significant effect on colony founding in C. pennsylvanicus. Two queens reared their first brood under artificial light.

Food preference studies of C. pennsylvanicus and C. ferrugineus indicated that these two species have similar food preferences. Although honey was preferred to most foods tested, it may not supply sufficient nutrients to ensure proper colony nutrition.

C. pennsylvanicus has become well adapted to man-made structures. Some foraging ants are present year round. C. pennsylvanicus optimizes its foraging by exploiting indoor and outdoor foraging sites.

The division of labor during nest construction may be based on subcaste. Major workers appear to be responsible for most nest-building in mature colonies.