Big Brown Bat (Eptesicus fuscus) Facts
The Big Brown Bat (Eptesicus fuscus) is native to Virginia and is found throughout the United States. Along with the Little Brown Bat, it is one of Virginia's most common bat species. While natural roosting sites include caves, hollow trees, and rock crevices, Big Brown Bats frequently roost in man-made structures such as attics, churches, apartment complexes, warehouses, and commercial buildings in Alexandria, VA.
Big Brown Bats are medium-sized bats weighing 1/2 to 5/8 oz, with a body length of 4 to 5 inches and a wingspan averaging 11 to 13 inches. They feature long, glossy dark brown fur with a black muzzle, ears, and wing membranes. Although not listed as a federally endangered species, Big Brown Bats are highly protected and beneficial mammals that play a critical role in insect control.
Life Span & Behavior of the Big Brown Bat
Big Brown Bats can live over 20 years in the wild, though their average lifespan ranges between 18 and 19 years. Mating occurs sporadically between November and March. Following mating season, females form maternal colonies—often selecting attics in Alexandria homes as roosting sites. Pups are born between May and early June. In Virginia, female Big Brown Bats typically give birth to two pups per year, whereas western U.S. populations usually produce a single pup.
Big Brown Bats are non-migratory and often utilize the same hibernacula for both summer roosting and winter hibernation, provided the area remains dark and maintains stable temperatures between 32°F and 50°F. Like many North American bat species, Big Brown Bat populations were impacted by White-Nose Syndrome, a fungal disease identified in 2006–2007 that severely affected hibernating bat colonies across eastern North America.
Big Brown Bat Diet
Big Brown Bats are strictly insectivorous, consuming agricultural and household pests such as beetles, moths, wasps, and mosquitoes caught mid-flight. A single colony can consume millions of insects nightly, providing natural pest control across Northern Virginia.
For more information on Virginia bats or to schedule professional service, contact Xceptional Wildlife today at (800) 373-3411 for complete Alexandria bat removal and exclusion solutions.