In the SE Peruvian Amazon, large numbers of frugivorous bats regularly visit natural forest clearings known locally as collpas (which are also referred to as clay licks or mineral licks). Bats arrive at collpas to drink water that has accumulated in depressions created by larger geophagous mammals that consume exposed soil. Although collpa visitation is common, little is known about its causes and its ecological implications for the bat community. We compared patterns of use of collpas and non-collpa forest sites by bats in SE Peru. We mist netted bats at collpas and non-collpa sites during the dry season and compared abundance, species richness, species composition, sex ratio, and reproductive condition. More species were captured at collpas than at non-collpa sites, and collpas were visited almost exclusively by frugivores. Overall, bat-capture frequency and combined frugivorous bat-capture frequency were higher at collpas than at non-collpa sites, although some species of frugivorous bats were captured more frequently at non-collpa sites than at collpas (e.g., Carollia spp.). Irrespective of capture site, more female bats were pregnant or lactating than not, but there was a distinct female sex bias in bats that visited collpas: 70 percent of bats captured at collpas were female, whereas 44 percent of bats captured away from collpas were female. These patterns suggest that collpas may provide important resources for frugivorous bats in SE Peru, just as they are thought to provide important resources to the vertebrates that consume collpa soils. Accordingly, collpas are important conservation targets in the region. © 2008 The Author(s).