Subscribe | UPI Odd Newsletter Subscribe Nov. 18 (UPI) -- Highways and roads have been shut down on an Australian island for an annual occurrence: the migration of millions of red crabs. The red crabs of Christmas Island migrate every autumn from their homes on the island to the ocean, and many highways and roads are shut down to protect the traveling animals from vehicles. Advertisement Some roads that remain open have been outfitted with special bridges the crabs use to avoid traffic, and other roads are cleared by workers with rakes before vehicles come through. Videos captured on the island show massive numbers of crabs walking in tandem with pedestrians. "Merry Crabsmas," Parks Australia quipped in a Facebook post featuring video of the migrating animals. Parks Australia tweeted that some residents have ended up stranded in their neighborhoods for a day at a time when large numbers of the crustaceans led officials to institute a "Crab Lockdown." Read More Ripley's attempting world record for largest ball of human hair Kitten rescued from atop utility pole in California Maryland man's lucky feeling leads to U-turn, $2 million lottery prize