Global biodiversity patterns are shaped by landscape structure and seasonality. Spatio-temporal patterns in bat assemblages are not well studied in grassland biomes but forest patches may provide important habitat for bats within these open grasslands. In the Greater Everglades Ecosystem (GEE), small fragments of diverse, critically imperiled pine rockland remain amidst a vast expanse of seasonally flooded grasslands (marl prairies). We used acoustic surveys to investigate the use of pine rocklands and marl prairies by bats across 2 distinct seasons (drycool and wet-warm). We detected higher mean bat activity in pine rocklands than marl prairies in the dry-cool season and higher bat species richness in pine rocklands in both seasons. Four of the 9 species of bats exhibited higher mean activity in pine rocklands than marl prairies and higher activity in the wet-warm season. The greater structural complexity of pine rocklands relative to marl prairies may be attractive to bats for roosting, foraging, and protective cover. Our finding of an interactive effect between vegetation community and season on bat activity suggests that pine rocklands may be more attractive to bats in the dry-cool season. This may be due to microclimate moderation, which likely leads to higher insect abundance for foraging bats. Pine rocklands in the GEE clearly provide ecological benefits that help support local biodiversity. These forest patches are important landscape elements for bats in grassland communities, where available roosts, prey, and protective cover may be limited.