Bat prevent them from spending too much time in unfamiliar places, and decrease predation. In some species, pregnant individuals may not use torpor. The smallest bat is Kitti's hog-nosed bat ("Craseonycteris thonglongyai"), which is long with a wingspan and weighs . It is also arguably the smallest extant species of mammal, next to the Etruscan shrew. The largest bats are a few species of "Pteropus" megabats and the giant golden-crowned flying fox, ("Acerodon jubatus"), which can weigh with a wingspan of . Larger bats tend to use lower frequencies and smaller bats higher for echolocation; high-frequency echolocation is better at detecting
Egyptian slit-faced bat a few to thousands of other members. Because they can maneuver in crowded habitats, they are able to occupy caves and holes that cannot be accessed by other bat species. While the bats do form a communal roost, individuals do not huddle together to conserve energy and warmth. They occupy two roosts, using the daytime roost to rest, while only spending a few hours in the night roost before going out to forage. They have a long-night foraging period, lasting several hours. The bats use high-frequency and low-intensity echolocation calls to locate prey. The low wing loading and low aspect