Every summer, the Bracken Bat Cave in southern Comal County is home to 20 million Mexican free-tailed bats - the largest bat colony in the world.

At dusk, millions of bats in the form of a "bat-nado" emerge from the cave in search of food.

After eating a collective two tons of bugs across South Texas, the bats return to the cave in the morning, where they remain safe and sound until hunger strikes again.