It's late afternoon in the swampy marshy forests of Kisanka National Park in Zambia.

Birds are flitting from tree to tree, and wild orange and white striped anelopes run through

the marsh grass.

Then at dusk you come across a patch of forest that feels empty.

The tree branches bow under the weight of big bunches of fruit, maybe bananas.

This fruit seems to be making noise, rustling and chirping, and it's getting louder and

more frenzied as the sun sets.

That's when you realize that these heavy bunches of bananas have eyes, and they're not actually

bananas at all.

They're bats.

At first, a handful of these bats lift off from the trees.

They're wing silhouetted against the orange sunset, but then, like they've been given

some kind of signal, the rest all follow.

Huge clouds of bats take off and fill the air, swirling around, squeaking and flapping

their wings.

You end up with just black dots all around you, as far as you can see.

You have millions and millions of bats flying out, filling the skies in all direction.

I'm Amanda McGowan, and this is Atlas of Skiura, a celebration of the world's strange

incredible and wondrous places.

And today we're taking you to Kassanka National Park in Zambia.

Every fall, this park hosts one of the largest and most mysterious mammal migrations on the

entire planet, going a little batty after this.

...