Starfish are really weird.

They have no blood and no brains. They eat by vomiting their stomach out of their mouth and engulfing prey within it. They move around on thousands of tiny tube feet. And many have the extraordinary ability to regenerate lost body parts—some can even form an entirely new sea star from a single “arm” and part of the central disk.

Recently, scientists have learned that these marine invertebrates may be hiding further weirdness. Previously, it had been suggested that starfish have no head. Now, DNA analysis indicates they’re actually all head.