Rebecca Ward, of Westland High School, asks :-
Why do cats fall on their feet even when dropped upside down?
Michael Tarttelin, a nuerophysiologist who is also Director of the Feline unit at Massey University, responded.
Cats are climbers so have evolved methods for making sure if they fall they can land on their paws safely and be able to catch their prey or run away from danger.
The secret of the cat's righting skills is a clever mechanism in the inner ear, called the balance organ or labryinth, which tells the cat's brain that it is falling and sets up a rapid series of nervous signals which are purely reflex. These signals would happen if the cat had its eyes closed. The result is that the cat's head takes on an upright position followed by its neck, shoulders and fore paws, back and hind paws and finally tail. It is a smooth wave-like progression all started by this inner ear mechanism.
I have tested the ability of a cat to right itself by holding it upside down and suddenly releasing it, usually onto a cushion. I have found that you can lower cats almost to within 75 mm of the ground and still some cats can right themseleves and land on four paws. When they are closer to the ground than 75 mm, they may only get the front half of their body righted.