Thomas's sac-winged bat

Thomas's sac-winged bat (Balantiopteryx io) is a small insect-eating bat of the family Emballonuridae found in Belize, Guatemala and Mexico. Oldfield Thomas named it in 1904, and it is presumed that he chose io after the figure of Greek mythology because bats seem flighty. It is the sister species of the Ecuadorian sac-winged bat, has no recognised subspecies, and is the smallest member of its genus, lacking the white trim that marks the gray sac-winged bat. Males weigh about 3.7 g and females about 5 g. The bat prefers to roost near the entrance of caves, though it has also been found deeper inside and in railroad tunnels, in colonies of fifty or more that hang at least about nine inches apart. It feeds on insects after sunset. The IUCN lists it as Vulnerable with a decreasing population, because about 30 percent of its natural habitat has been destroyed by vandalism, fires in caves and tourism.