Little brown bats are predators of flying aquatic insects. Little brown bats are one of seven North American bat species affected by the fungal disease, White Nose Syndrome.
Little brown bats typically reach 3.5 inches in length, with a wingspan of 9 to 11 inches. Females are a bit larger than males. These bats have glossy brown fur with blackish faces, ears and wing membranes. When seen up close, the hind feet have hairs that extend beyond the tips of the toes. Little browns are small bats that rarely reach a 0.5 ounce in weight.
Little brown bats use echolocation to hunt flying aquatic insects like mayflies and midges but also take gnats, wasps and moths. Most bats eat half their body weight each night, with nursing females eating over 100 percent of their body weight. While actively hunting airborne prey, little brown bats emit echolocation calls over 200 times each second. They are also capable of flight speeds of over 20 miles per hour.
Since 2006 a devastating fungal infection, white nose syndrome, has killed over six million bats, mostly in the eastern United States. Little brown bats are one of seven cave-roosting species affected. The disease causes bats to become too active in the winter, when they should be hibernating, and damages their wings and causes severe weight loss.