Our bodies do a decent enough job of repairing themselves, able to patch up wounds, fight off infections and even heal broken bones. But that only applies up to a certain point – lose a limb, for example, and it’s not coming back short of a prosthesis. Other creatures have mastered this skill though, and now scientists at the University of California Davis (UC Davis) and Harvard have sequenced the RNA transcripts for the immortal hydra and figured out how it manages to do just that.