Horseshoe crabs have a unique reproductive strategy.

The female horseshoe crab, with a male horseshoe crab in tow will come up to the shore line and lay up to 20,000 eggs in a number of shallow nests that she makes along the beach.

After laying the eggs she pulls the male over the nest when he then fertilizes the eggs.

It’s a good thing that she lays so many eggs because they then leave the nest unattended and the eggs are then open for predators to eat, mainly shorebirds.