Axolotls are nature’s great regenerators. They are able to grow back not just their tails, but also legs, arms, even parts of vital organs, including their hearts. This remarkable ability is one of several traits that turned the axolotl into a scientific superstar. The axolotl is one of the most abundant laboratory animals in biology. They can be found swimming in tanks at universities all around the world. But in the wild they’ve only ever been found in one place: Mexico City.Model Organism