Big Brown Bat


Big brown bat (Eptescius fuscus)


Total Length

3.8 to 5 inches  (9.6-12.7 cm)


11 to 25 grams


12.5 to 13.7 inches (32-35 cm)

Back fur color

Glossy cinnamon to dark brown

Belly fur color

Slightly lighter


Broad and rounded

Distinguishing characteristics

Muzzle and ears hairless and typically black 

Roost Pattern
















  • Found in caves, forests, loose bark and cavities in trees, rock crevices, buildings and other man-made structures. Can be found in urban areas.

Food Habits

  • Usually emerge early in the evening
  • Feed on flying insects such as mosquitos, mayflies, flies, beetles, cockroaches   
  • Typically follow a regular pattern and forage close to the crowns of trees


  • Throughout the United States, and from southern Canada to British Columbia and south to Baja California. Also found in most of Mexico and Central America to Panama, eastward to Florida and the Atlantic Coast

Range Map from Tennessee Bat Working Group


  • Mating occurs in fall
  • Young born May to July
  • Litter size 1 pup in western North America and 2 pups in the eastern North America
  • Young able to fly at 4 to 5 weeks of age
  • Maternity colonies can vary from a few individuals to several hundred individuals