To determine if salinity of water and presence of vegetation influence use of wetlands by bats, acoustic detectors were used to record echolocation calls of bats over wetlands in Charleston County, South Carolina, during June– October 2014. Abundance and diversity of insects were determined using a light trap and environmental conditions were measured with a portable weather station to determine if availability of insects or environmental conditions, respectively, played a prominent role in where bats were active. Bats were significantly less active over wetlands with vegetation compared to open-water habitats. Salinity of water played a less significant role than presence of vegetation in where bats were active; however, freshwater sites had the greatest activity. Abundance and diversity of insects were not related to activity of bats. Environmental conditions were related less to activity of bats than features of the habitat. Maintaining open-water areas devoid of vegetation is critical for encouraging activity of bats over wetlands.