Little Brown Bat

Myotis lucifugus

Summary 4

The little brown bat (sometimes called little brown myotis) (Myotis lucifugus) is a species of the genus Myotis (mouse-eared bats), one of the most common bats of North America. The little brown bat has been a model organism for studying bats.
The little brown bat lives in three different roosting sites: day roosts, night roost and hibernation roosts.[4] Bats use day and night roosts during spring, summer and fall while hibernacula are used in winter. Day roosts are usually found in buildings or trees, under rocks or wood piles and sometimes in caves. Nursery roosts are found in both natural hollows and in buildings (or at least close to them). Nursery roosts have also been found under the sheet metal roofs of trappers' caches[5] and attics of buildings.[6] Night roosts tend to be in the same buildings as day roosts, but these roosts tend to be in different spots that are more constrained and the bats pack together for warmth. Bats rest in night roosts after feeding in the evening which may serve to keep their feces away from the day roosts and thus less noticeable to predators.[4] Brown bats typically hibernate in caves and perhaps unused mines. Northern populations of bats enter hibernation in early September and end in mid-May while southern populations enter in November and ends mid-March.[4] Little brown bats are not true hibernators. As observed in the Mid-Atlantic States during periods of warming during the winter, typically over 50 degrees (F), little brown bats emerge from their winter torpor and hunt insects that have emerged as well in response to the warmer conditions.
The average sleep time of a little brown bat in captivity is said to be 19.9 hours per day. This long period of sleep is thought to be a way of conserving energy, by only hunting for a few hours each night when their insect prey are available.[14]
As with most bats, the little brown bat is mostly active at night and leaves its roost at dusk and the next two or three hours are peak activity periods. They are also active before dawn. Since little brown bats live in a temperate zone, they must find some way of dealing with winter. Most temperate bats either migrate or hibernate, but little brown bats do both. In summer, the males and females live apart, the females raise the young. When fall comes, both sexes fly south to a hibernaculum, where they mate and then hibernate. Little brown bats undergo a prolonged period of hibernation during the winter due to the lack of food. They hibernate in caves as a community.

Sources and Credits

  1. (c) Zack, some rights reserved (CC BY-NC-SA),
  2. (c) Phil Myers, all rights reserved, uploaded by nataliemarisa,
  3. (c) Phil Myers, all rights reserved, uploaded by nataliemarisa,
  4. Adapted by nataliemarisa from a work by (c) Wikipedia, some rights reserved (CC BY-SA),

More Info

iNat Map

Endangered status least concern
Taxa mammal