Females mature sexually at about 8 months of age, while males mature in their second summer. Little brown bats may live more than 30 years. Similar in size and color to the little brown bat, the northern long-eared bat may be distinguished by its longer tail and narrower and longer ears. Biologists have learned little of the ecology and behavior of the northern long-eared bat, although they suspect feeding habits are similar to those of the little brown. Long-eared bats roost singly or in small colonies in caves, behind window shutters, under loose tree bark, in cliff crevices.
Females gather in nursery colonies in attics, barns, and tree cavities.
Probably a single young is born in July. Long-eared bats return to caves in fall, often sharing space with little brown bats, big brown bats and pipistrelle bats. The Indiana bat resembles the little brown bat, but has a pinkish cast to its fur, giving it a light purple-brown coloration. Sexes are equal in size. In winter, some 97 percent of the total species population hibernates in certain large caves in Missouri, Kentucky, Indiana, and Illinois.