The big brown bat (Eptesicus fuscus) is native to North America, Central America, the Caribbean, and extreme northern South America. his medium-sized bat ranges from 10–13 cm (3.9–5.1 in) in body length, with an 28–33 cm (11–13 in) wingspan, and weighs between 14–16 g (0.49–0.56 oz). The fur is moderately long and shiny brown. The wing membranes, ears, feet, and face are dark brown to blackish in color.Like all bats, big brown bats are nocturnal, roosting during the day in hollow trees, beneath loose tree bark, in the crevices of rocks, or in man-made structures such as attics, barns, old buildings, eaves, and window shutters. Big brown bats navigate through the night skies by use of echolocation, producing ultrasonic sounds through the mouth or nose. They are known also to produce audible sound during flight, a click or a sound like escaping steam.