Breeding horseshoe crabs are invading US beaches

Hundreds of horseshoe crabs have started to make their way onto the shore at New Jersey beaches to mate.

The third week of May marks the tradition that sees the female crabs lay their tiny green eggs in the sand.

According to the New Jersey State Park Service, the world’s largest concentration of these crabs - which are actually an ancient cousin of the scorpion - can be found on Delaware Bay.

Thousands of eggs are expected to hatch at the next full moon - but only if they don’t get eaten by birds.