Watch: Millions of red crabs begin annual migration on Christmas Island

Tens of millions of crabs have begun their annual migration on Christmas Island, turning the roads and undergrowth into a carpet of red.

The island, located off mainland Australia and near the Indonesian island of Java, experiences the spectacular event every summer, when around 50 million of them move from their homes down to the beaches to lay their eggs.

Special crab bridges have been built on the island to help the crabs get around tricky obstacles like roads, and local radio stations provide people with an update on their movements.

The migration will culminate in a major spawning event around mid-November, followed by a second spawning one month later, according to Parks Australia, with baby crabs returning to shore in the new year.