How do axolotls regrow parts of themselves?

By rebuilding instead of scarring. Where most animals seal a wound with scar tissue, an axolotl gathers a bud of unspecialised cells at the injury, and those cells then work out what they need to become.

It can regrow a whole limb, bone and nerve included, and repair parts of its heart and brain. Scientists study them closely, hoping to understand how they manage it.