Brazilian free-tailed bats are named for the long tails that extend beyond their uropatagium (membrane surrounding the tail). Like other species of the family Molossidae, Brazilian free-tailed bats have distinctive large, rounded ears that form a semicircle around the face and nearly meet on the forehead. They are a fast flying bat and have been clocked at speeds up to 60 mph. This species is know for its extremely large colonies;  the largest, Bracken Cave, is home to more than 15 million individuals. Brazilian free-tailed bats commonly roost in caves, bridges, and buildings. They are generalist feeders, preying on moths, beetles, flies, and insects in the order Hemiptera. Females typically give birth to a single pup each summer. The average lifespan of Brazilian free-tailed bats is 8 years.