This morning we awoke to find a sleepy Little Brown Bat, as opposed to a Big Brown Bat, fast asleep in the dining room curtains. It’s a mystery how he got in and why it took so long to wake him up. Once outdoors, he spread his wings and flew over the fence and into our neighbor’s trees.
Bats, our only flying mammals, are truly remarkable animals. It’s too bad their unwarranted reputation has prevented many people from appreciating how beneficial and unique they are.
Bats belong to the order Chiroptera, which means “hand-wing.” Their wings are composed of two thin layers of skin or membrane, attached to elongated finger bones. Each membrane has four fingers and a thumb, which control the wing’s movement. The thumb, located at the top of the wing, acts as a hook with which the bat is able to crawl on flat surf
The two most common bats found in Massachusetts are the little brown bat (Myotis lucifugus) and the big brown bat (Eptesicus fuscus). Both have short, soft fur covering their head and body and rich brown bodies with slightly darker brown wings.
The body of a little brown bat measures 4½ to 5½ inches long, including the tail, and has an 8½ to 10½ inch wingspan. The big brown bat’s body ranges from 5½ to 8 inches in length with a 12 to 13 inch wingspan.
In the spring and summer, females of little brown bats form colonies consisting of hundreds of individuals. Big brown bats, which prefer the more urban areas inside Route 495, are usually found in colonies of less than two hundred bats.