Millions of red crabs migrate on Christmas Island

A sea of red crabs was seen on the Australia territory of Christmas Island as the crustaceans made their annual migration from the forest to the coast.

Photographer Andrew Watson shared a time lapse video of the crabs' journey over stairs, rocks and bridges to water.

According to Parks Australia, the crabs migrate at the beginning of the wet season between October and December. They migrate to breed and spawn.

"Eggs are released by the female red crabs into the sea precisely at the turn of the high tide during the last lunar quarter," the organization said on their website.

Parks Australia calls the red crabs a "keystone species" for Christmas Island, with a population of tens of millions.