Thirty forested plots throughout Connecticut were established to determine the associationof forest site conditions with population sizes of common ants (Hymenoptera: Formicidae).The plot characteristics investigated were plot slope, elevation,longitude,latitude, basal area of trees and number of understory stems of species associated with moist conditions, and total length of intersection of rocks along 4 plot transects.Two plot characteristics were consistently related to ant abundance: plot latitude and basal area of trees that prefer mesic or wet sites. Ant numbers were less at high latitudes and in moister sites. Implications of these results for improving biological control by ants are discussed.