Discover Nature: Brown Bats Breed

Oct 3, 2017

Myotises, or little brown bats, gather at cave and mine entrances to mate before hibernation each fall. Once common across the state, these bats are now disappearing due to impacts of white-nose syndrome. They are protected under state and federal laws, and designated a Species of Conservation Concern in Missouri.
Credit Missouri Department of Conservation

This week on Discover Nature keep your eyes peeled around dusk for groups of little brown bats.


Little brown myotises, or mouse-eared bats are only about three to four inches long, and weigh only a quarter of an ounce. They have yellowish- to olive-brown fur with a glossy sheen.

In the fall, these bats gather at cave and mine entrances to mate before hibernation. However, fertilization of the ovum will not take place until spring, and mothers will bear a single offspring by mid-June.

These nocturnal mammals help control pests such as mosquitos, eating up to half their body weight each night.  Many forms of cave-dwelling life also depend on the nutrients brought in by bats and released from their guano.

The little brown myotis is a Species of Conservation Concern in Missouri.  Once common across the state, this species has declined dramatically due to impacts of white-nose syndrome. They are protected by both state and federal laws to prevent losing this species forever.

Learn more about the little brown myotis, and other Missouri bats with the Missouri Department of Conservation’s online field guide.

Discover Nature is sponsored by the Missouri Department of Conservation.