Nine species of bat are known to occur across the six New England states, but most aspects of their natural history, such as foraging habitat use, are poorly understood. Recent published research has documented the importance of still-water habitats as foci of bat flight activity. To better understand and document habitat use in southern New England, we used the AnaBat II acoustical monitoring system to assess species composition and relative levels of summer flight activity. Active acoustic surveys were conducted in six habitat types on the Quabbin Reservation in central Massachusetts in 2003 and 2004. Bat flight activity, as measured by numbers of echolocation call sequences, was high, with an average of 24 search-phase and 4 feeding-buzz calls per 20-minute survey period. Myotis lucifugus (little brown bat) was the most commonly recorded species. Bat flight activity was high over all still-water habitats, but greatest over large ponds. Large-bodied bats, such as Eptesicus fuscus (big brown bat), were recorded more often in open, structurally uncluttered habitats. Of the small-bodied bats, little brown bats were ubiquitous, whereas Myotis septentrionalis (northern myotis) was most common in structurally cluttered habitats of seasonal forest (vernal) pools and along forest streams. Generalized habitat associations among the bat species we recorded are similar to those reported for other New England forest sites. The Quabbin Reservation is an excellent site to continue examining bat-habitat relationships because of the abundance and diversity of aquatic habitats, in both cluttered closed-canopy and uncluttered open-canopy settings.