Why do rats have naked tails?

A rat’s tail is actually covered with scales and fine hairs that help it grip things like branches, ropes, and drain pipes. A rat also uses its tail for balance — kind of like a tightrope walker uses a pole.

A rat’s tail also acts like a built-in air conditioner or heater. When a rat is too hot, it pumps more blood to its tail. Because there is no fur on the tail, the extra heat can escape from the skin. When a rat is too cold, the opposite occurs. Less blood flowing to the naked tail means the rat stays warmer.