Brightly colored Velella velella, tiny jellylike creatures with stinging tentacles, have invaded California beaches by the thousands, baffling beachgoers and drawing attention from marine biologists. These by-the-wind sailors—named for their sail-like skin flap—rely on wind to traverse oceans but are now stranded en masse from Baja California to Alaska due to strong spring gusts. Experts note their appearance is cyclical, occurring every few years when wind patterns align, though their sheer numbers this season have sparked widespread social media fascination.