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
Lesser sac-winged bat the tree canopy. The lesser white-lined bat feeds primarily on aerial insects in the order Hymenoptera. This includes flying ants and formicids. The bats forage in areas under tree canopies and use echolocation to hunt the flying insects. The bats don't change their calling frequency or their mouth size when using echolocation while hunting. When roosting, the bats usually form small groups anywhere from 2 to a 9. Additionally, the bats are thought to be monogamous which is rare for most mammals. Females typically only produce one or two young per year. The young can't fly for about the first