Out of the order of mammals called Chiroptera, which contains over 800 species world-wide, there are at least eight species of bats living in Yellowstone. This little brown bat is common in Yellowstone. All Yellowstone bats are insectivores, and most of their prey is caught in flight using echolocation. Echolocation allows the bat to avoid obstacles and to find flying insects. A little brown bat catches insects in its interfemoral or tail membrane or in its mouth. It will often grab the insect in its mouth and simultaneously bring its tail membrane forward to hold the insect for a moment to get a better grip, swallow the insect, then fly on, all of this happening within one wing cycle. This maneuver makes it almost turn a backward somersault. Individuals leave roosts in buildings, caves, or trees at dusk to forage for several hours traveling over water, along the edges of wooded areas, and over open grasslands, eating an average of nearly 500 insects per hour. The bats do not migrate but hibernate from late September or early October until April or May.