Look, but don’t touch. That’s the message from marine biologists as Southern California experiences an invasion of jellyfish-like creatures known as Velella velella, or By-the-Wind Sailors.

On Saturday, Dana Wharf Whale Watching posted a video of the strange blue and purple-ish blobs that travel in the open ocean through currents and winds.

Beachgoers are seeing them wash ashore by the hundreds along the Southern California coast, including Huntington Beach, Zuma Beach, Manhattan Beach, and Salt Creek Beach. They have also been spotted farther north.

By-the-Wind sailors are known as colonial hydroids and are comprised of a colony of tiny creatures, similar to the Portuguese Man O’War. They feed on algae and zooplankton and are a favorite meal for sunfish, according to Nona the Naturalist with Dana Wharf Whale Watching.

Like jellyfish, By-the-Wind Sailors also have stinging cells, so marine biologists say people should avoid touching them. But generally, they are not considered to be dangerous to humans.

Experts say Velella velella are frequently seen on beaches around the globe when strong winds, like those from California’s historic winter storms, push them ashore.