...cats always land on their feet?

Is it just a figure of speech that cats always land on their feet, or is it actually true? If so, why don’t all animals do this?

If a cat falls more than about a metre, it will land on its feet no matter the initial position – unless it is sick or otherwise impaired. From this height the cat has time to rotate its body in the air on its way down. Biologists have named this ability a righting reflex. The ability to rotate in the air requires special adaptations of the cat body, such as a very flexible spine and a well-developed organ of balance that will quickly allow the cat to orientate itself as it falls.

But even animals with a righting reflex can nevertheless suffer damage in a fall.

In 1984, American scientists studied how early cats develop the righting reflex. Their results show that kittens master the basic method by around age 3-4 weeks, and a few weeks later they will carry out perfect rotations in the air. Over the course of their evolution, the domestic cat’s wild ancestors developed the ability because they caught their prey in trees, from which they risked a dangerous fall.

According to biologists, almost all the members of the cat family have the righting reflex. But in several heavier species such as the mountain lion and the tiger, they cannot endure falling very far even if they do land on their feet.

Other animals that risk falling because of their way of life have developed their own versions of the righting reflex, including guinea pigs and rabbits.