Every night, something extraordinary happens in the world's oceans.

Millions of animals rise from the darkness below.

They travel upward toward the surface.

They feed.

And then, before daylight returns, they disappear back into the depths.

This happens across enormous areas of the world's oceans every single night.

It is one of the greatest movements of life on Earth.

And most people never see it.

In The Largest Migration on Earth Happens Every Night, we descend into the deep ocean to explore the remarkable phenomenon known as diel vertical migration.

The animals involved are often tiny.

The ocean's darkness becomes their shelter once again.

This creates a daily vertical rhythm that connects the surface ocean with the deep.

We explore the rem ...