Mexican free-tailed bat (Copyright photo by Merlin D. Tuttle, Bat Conservation International, www.batcon.org)

Tadarida brasiliensis

Subspecies: T. b. Mexicana (migratory)

T. b. cynocephala (non-migratory)

Wingspan: 11–14 in.

Length: 3½–4 in.

Weight: 0.28–0.49 oz

Color: Gray or dark brown to rusty brown

Other: Large round ears and vertical wrinkles on upper lip; tail projects beyond the tail membrane for about a third of its length

Roosting behavior: Can maintain mega-colonies of more than 1 million bats.

Human encounters: The species most likely to encounter humans. Lives in bridges, buildings, and any abandoned structure. Will occupy bat houses