Watch a terrifying 'tornado' of 20 million swarming bats

USFWS/Ann Froschauer/Flickr

Crazy, right?

When dusk falls, 20 million Mexican free-tailed bats swoop out of Bracken Cave near San Antonio, Texas.

After spending the winter in Mexico, the bats fly north to procreate. By August, the pups can fly and the colony size reaches its peak.

Each night, the Bracken bat colony can eat 200 tons of moths, according to the Texas Parks and Wildlife Department.

Feel what it's like to stand at the cave's entrance in this awesome video from National Geographic:

Were you as excited as these US Forest Service staff members were? Not possible.

USFWS/Ann Froschauer/Flickr