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
Long-legged bat family Phyllostomidae that use low-intensity “whispering” echos, the Long-Legged Bat has been shown to produce high-intense echolocation calls to detect its prey. M. macrophyllum will adjust the intensity of its calls depending on the environment that it’s in. When in areas with high acoustic clutter, the bats will decrease their signal intensity, while in more open areas, the bats will increase their signal intensity. By increasing call intensity in a more open environment, this allows these bats to have a broader detection range for food. Average intensity output has been shown increase by 11 dB, corresponding to a 4x amplitude