On the islands of Palau, tiny land-locked lakes are home to the jellyfish. Each day, the jellies make a half mile migration across the lake. They move to avoid a lethal enemy - the sea anemone. A jellyfish snared by the stinging tentacles is slowly digested by the anemone and helpless to escape other hungry marauders. A seemingly passive swarm navigates using the sun. Swimming east in the morning and west in the afternoon ensures the jellies always encounter a shadow before the actual side of the lake. A single swarm contains up to 24 million jellies.