You'll Never Guess Where Earth's Largest Migration Happens

The biggest (and most mysterious!) migration in the world happens every night in the ocean as 10 billion tons of zooplankton swim to the surface to feed. This undersea journey is known as Diel vertical migration, and it occurs in every ocean in the world. By learning more about why this happens, science can unlock the secrets behind other phenomena, like our biological clocks…and even climate change.