Millions of red crabs take over Australian island in annual spectacle

Millions of red crabs have taken over an Australian island in their annual migration spectacle.

The parade of crustaceans can be seen yearly on Christmas Island during the migration season, which starts with the first rainfall of the wet season — usually in October or November but sometimes as late as December or January.

They swarm across roads, streams, rocks and beaches as they emerge from the forest and head to the ocean to breed.

Christmas Island National Park describes red crab migration as "one of the most incredible natural processes on Earth."

Sir David Attenborough called the sight one of his greatest TV moments.