The Big Brown Bat is a relatively large bat species that can grow up to 5 inches long and weigh up to 5 ounces. They have brown fur and dark brown to blackish wings, ears, feet, and face. Young bats are born in late May or early June and begin flying on their own after 3-4 weeks. Big Brown Bats roost in hollow trees, under tree bark, in rock crevices, attics, barns, and old buildings. They are an important predator of insects like mosquitoes and beetles. Big Brown Bats have a wide range across North and Central America.