Watch an estimated 20 million Mexican Free-tailed Bats (tadarida brasiliensis) swirl up, up, and out of Bracken Bat Cave in this comprehensive report by Texas Country Reporter Bob Phillips. We also get a peek inside the neighboring Natural Bridge Caverns, a limestone-filled National Natural Landmark.

A natural wonder, Bracken Cave is protected by Bat Conservation International. From’s webcam page:

The world’s largest bat colony spends its summers in BCI’s Bracken Cave in the Texas Hill Country near San Antonio. The bat mothers and pups of this maternity colony of Mexican free-tailed bats eat tons of insects every night, including many costly farm pests. From March to November, the bats’ nightly emergence from the cave takes more than three hours and includes so many bats that they show up on Doppler radar…

Enjoy this quiet moment of emergence as millions and millions of mother and baby bats swarm out into the evening sky:

Related reading: Nat Geo Kids’ Amazing bats of Bracken Cave.

Related videos, elsewhere: It’s Okay to Be Smart’s Bats: Wonders of the Night, and on this site: hand-raising an orphaned short-tailed fruit bat and the Tube-Lipped Nectar Bat’s crazy-long tongue.

See more videos about...