Among any and all creatures in this world that could be considered living, including people, there is an universal truth: We die. But not all of us go through the gradual (and eventually rapid) process of self-destruction that we think of ageing. Some animals and plants, such as species of jellyfish, tortoises and trees, seem to have a sort of biological immortality. A recent study published in eLife provides more evidence there's at least one more animal we should add to that list: The naked mole-rat.