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
Waterhouse's leaf-nosed bat happen in that last trimester. Like many bats, this species uses echolocation as a means to locate their prey. In particular, "Macrotus waterhousii" uses a low intensity, broadband-like call to aide in their search for food. The maximum frequency of a call is 73.65 kHz with a minimum of 46.19 kHz, creating a bandwidth of 27.46 kHz. The call ranges from about 1 second to 3 seconds. In addition, to echolocation, "M. waterhousii" uses the sound made by the prey itself to locate it. This type of foraging behavior leads to a preference for a cluttered habitat. As "M. waterhousii"