The video above shows a particularly eventful visit to Bracken Cave. According to Bat Conservation International, Bracken Cave—located just outside of San Antonio, Texas—is the summer home of the world’s largest bat colony. We hope you like bats, because there are estimated to be about 20 million of them in there.
Early in the day, filmmaker/photographer Cristian Dimitrius and conservationist Fran Hutchins arrive at the mouth of the cave and set up some GoPro cameras. They also have a camera drone ready to go. Then, they sit and wait.
As the afternoon winds down, it begins. Hundreds, then thousands, then millions of insectivore Mexican free-tailed bats swarm from the cave and into the skies on their way to dinner. It’s a raging blizzard of bats. They're about 3.5 inches in length and weigh a little less than half an ounce.
By the time the sun kisses the horizon, the bats are all out looking for bugs, leaving behind their empty bat cave and two very exhilarated humans.
Correction, Feb. 3, 2016: This post originally misstated that the bats in the video are free-tailed bats. They are Mexican free-tailed bats. Information about the species has been updated.