The Big Brown Bat (Eptesicus fuscus) is larger in size than comparative species of bats, from about 4 to 5 inches (10 – 13 cm) in body length, with a 11-13 inch wingspan and weighing 1/2 to 5/8 ounce. The fur is moderately long, and shiny brown. The wing membranes, ears, feet, and face are dark brown to blackish in color.