The big brown bat is reddish to dark brown in color, and sports a wingspan ranging from 12 1/2 to 13 1/2 inches. Its slow, steady flight, and large size make it fairly easy to identify. They are late-dusk fliers that often swoop low to the ground. A colonizing species, big browns roost in buildings and under bridges in summer and hibernate in caves, mines, houses, hollow trees, and even storm sewers in winter. Efficient feeders, the species often roosts for a short nap after gorging itself. Porches, garages, and breezeways are good places to find them. The female gives birth to only one pup per year. 

 

The little brown bat is especially abundant throughout the state and is the most common species. A light brown to dark brown in color, little browns are fairly small in size with a wingspan of 8 1/2 to 11 1/2 inches. In summer, colonies of them live in hot attics and under shingles and siding; in winter, they hibernate in caves, houses, hollow trees, or mines. Females form nursery colonies away from the males. Little brown bats like to feed on aquatic insects such as mosquitoes and can eat up to 600 to a 1,000 an hour. They frequently are seen dipping and diving over water but will also forage over lawns and pastures, among trees, and under street lights.

 

The hoary bat is Michigan’s largest with a wingspan of up to 15 inches. Heavily furred, the hoary's dark-colored hair is tipped with white giving it a frosted appearance. It’s rarely encountered by people and migrates south for the winter. It is a solitary species that spends its summer months in trees near water throughout Michigan.

 

The red bat also migrates south and is a solitary bat of forests near water. Its long, pointed wings may stretch 12 inches. Color varies from a bright orange to a yellow-brown, and the males are usually brighter in color than the females. Like most other bat species, the red bat breeds in fall, the female gives birth in the spring and has one to four pups after a gestation period of 80 to 90 days.  

 

The silver-haired bat lives in forested areas near streams and lakes. Similar in size to the red bat, the silver-haired species is black or dark brown with silver on the tips of its hairs. Considered scarce throughout the state, the silver-haired bat is most easily identified by its slow flight, which is typically low to the ground. A solitary species, females give birth in June and July to two young. They also migrate south in winter.

 

The eastern pipistrelle bat does not migrate as it hibernates in caves or abandoned mines through the winter in the western Upper Peninsula where it lives year-round. This bat occupies rock crevices and building ledges during the day, and leaves just before sunset to feed on insects. A tiny bat with a wingspan of 10 inches or less, the pipistrelle is often confused with a large moth. Ranging from a golden brown to reddish brown.

 

The Federally endangered northern long-eared bat has very large ears that makes them easy to identify at close range. Similar in size to the silver-haired or red bat, the long-eared is brown in color. Although it typically roosts alone in buildings and under tree bark in the summer, small numbers hibernate together in caves, often with big brown bats. The species also forms small nursing colonies in hollow trees or under bark. 

 

The evening bat lives in southern Michigan and is easily confused with the little brown bat except the evening bat has a curved, rounded fleshy protrusion on the ear instead of pointed. Their wing span is about 10 to 11 inches. The evening bat flies low to the ground and is sometimes seen swarming around caves, which it rarely enters. Young are born in summer and litter size is typically two pups. 

 

The Federally endangered Indiana bat is considered rare in southern Michigan, the only region in the state where it can be found. A light brown in color, the Indiana bat closely resembles the little brown bat. They also will migrate south.