What animal doesn’t feel pain?

Naked mole rats are a truly bizarre animal that seem to break all the rules of what it means to be a mammal. They live in social groups like bees, ants, or termites. They have skin so loose they can turn almost halfway around in it. They are nearly blind and spend their entire lives underground. They don’t drink water. They are cold blooded. They are rodents but they live nine times longer than mice of the same size. And they don’t feel pain. So how does such an unusual animal exist?

Most of the mole-rat’s unique adaptations help it survive beneath the African soils where they make their homes. The colony is ruled by a queen: a large female and the only one that reproduces. Beneath the queen are the soldiers, who defend the colony from intruders or predators, and workers who dig the tunnels and find the underground roots that feed the colony.

Their loose skin allows mole rats to slide through tight tunnels without getting stuck. And though they are cold blooded, their colonies stay warm from the heat of their excavations. If they need to raise their temperatures, some mole rats will sit in sun-baked tunnels just beneath the surface and then return to the colony like living hot water bottles.

Have you ever bitten into a hot pepper and felt the burning pain on your tongue? Naked mole-rats don’t feel that kind of pain. When they breathe out underground, the carbon dioxide in their breath becomes extremely acidic against their eyes, noses, mouths, and skin. If they felt that kind of pain, mole-rats would spend their entire lives being burned. But their insensitivity to pain makes living underground a breeze!