Mexican Free-tailed bats are microchiropteras or microbats. An adult Mexican Free-tailed bat weighs about .42 to .53 ounces. Males are usually a little bigger than females. Mexican Free-tailed bats usually migrate to central Mexico. Their favorite food is moths, but they also eat beetles and flying ants.

There are three famous locations of colonies of Mexican Free-tailed bats. Bracken Cave in Texas has about 20 million bats. The colony eats about 250 tons of insects a night. Carlsbad Caverns in New Mexico is also a place with a lot of Mexican free-tailed bats. The third location is the Congress Avenue Bridge in Austin, Texas. It is home to about 1 million bats.