Aztec mastiff bat

The Aztec mastiff bat, Molossus aztecus, is an insect-eating bat of the free-tailed bat family Molossidae, found from Jalisco and Cozumel Island in southern Mexico south to Nicaragua. The Swiss scientist Henri Saussure described it in 1860, and the species name refers to the Aztecs of Mexico, where it was first documented. It is one of the smallest bats of the genus Molossus, weighing 12 to 16 grams with a forearm of 34 to 35 millimetres, and its fur is chocolate brown with very dark brown wing membranes, nose and ears. It is nocturnal, foraging for insects at night and roosting in hollow trees by day. Unusually for its genus, females may become pregnant while still nursing a pup. It lives in a variety of forest habitats, from near sea level to about 1,300 metres.