When spring comes to Philadelphia's Delaware Bay, the shore becomes covered with tens of millions of horseshoe crabs. It's spawning season. Learn more about this oceanic orgy in the Deep Look video above. The transcript reads like poetry:
When a female finds a good spot, she digs and digs into the wet sand.
The female lays roughly 4,000 eggs in one go.
The male that clung to her all this time is in the best position to fertilize the most eggs.
All those single dudes crowd around too, vying to fertilize the rest.
As the party winds down, the grown-ups start heading back to sea,
But they'll return for more of these high-tide soirees throughout the season.
They leave their fertilized eggs behind, buried in the damp sand.
Each one is smaller than a pea.