Description: Mexican Free-tailed Bats (Tadarida brasiliensis) are medium-sized, dark-colored bats with a tail that extends far beyond the tail membrane (uropatagium). The head and body are about 4-1/4-inches long, and the wingspan is about 12 inches. The ears are rounded, relatively short (do not extend beyond the muzzle), and are not joined across the forehead. The hair is uniform in color. The nose is simple.

Taxonomy: Order: Chiroptera, Family: Molossidae. Also known as Guano Bats and Brazilian Free-tailed Bats.

Diet: Forages in the open sky, flying fast and straight, catching insects (e.g., mosquitoes and moths) on the wing at night.

Habitat: Urban and wild areas with caves suitable for roosting and raising young.

Range: Southern tier of US states (all of California east to North Carolina) south to Central America. Winter in Mexico and Central America, then fly north for the summer.

Comments: This is the species of bat that blackens the sky in great, swirling clouds at Carlsbad Caverns (NM), Bracken Cave (TX), and the Congress Avenue Bridge in downtown Austin (TX). Around Las Vegas, look for this species at the Reid International Airport parking garage.