Little Brown Myotis

Myotis lucifugus

Order: Chiroptera

Suborder: Yangochiroptera

Family: Vespertilionidae

Call characteristics:

High frequency caller (~40 kHz range)


2 3/8 - 4 in

(6 - 10.2 cm)



1/8 - 1/2 oz

(5 - 14 g)


The little brown myotis has fur ranging in color from brown to yellowish to gray-brown. In the west of its range, the little brown bat prefers mountainous habitat and riparian areas in a variety of forest types such as xeric-scrub and aspen meadows. In addition, this bat can be found roosting amongst man-made structures such as buildings, attics, and bat boxes in towns and open, arid areas. They will also roost beneath the bark of trees or within tree holes, under rocks, and in woodpiles. The little brown myotis will consume a wide variety of aquatic insects from midges and mayflies to moths and beetles. Lactating females may eat up to half their body weight in insects a night while nursing their pups. During cold weather, the little brown myotis will hibernate within caves and abandoned mines in groups of tens of thousands of bats. This species is particularly susceptible to the fungal pathogen, white-nose syndrome, which has caused populations to decline drastically.

Conservation Status

Mexico - not listed
Image by Evan Wise


The little brown myotis is widespread across North America, occurring throughout Canada, Alaska, and much of the lower 48


Photo Credit: Nicole Besler




NABat utilizes monitoring data provided by a broad network of partners to support regional and range-wide inferences about changes in the distributions and abundances of bat populations facing current and emerging threats.

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Information used to populate this page was obtained from the following sources:


NatureServe Explorer

United States Fish and Wildlife Service Environmental Conservation Online System 

Bat Conservation International Bat Profiles

Taylor, M. 2019. Bats: an illustrated guide to all species. Washington, DC: Smithsonian Books.