Cats have an impressive ability to turn themselves upright while falling.
The behavior is called the righting reflex.
It develops when kittens are young and relies on balance, flexibility, and rapid body control.
The inner ear tells the cat which way is up
The balance system inside the inner ear detects orientation and movement.
When a falling cat senses that it is upside down, the brain receives information about which direction the body needs to rotate.
That begins the righting response.
Cats can rotate different parts of the body separately
A cat has a flexible spine.
It can twist the front half of the body in one direction while adjusting the back half in another.
The legs also change position to control how fast different sections rotate.
This allows the cat to turn without pushing against a wall or other object.
Spreading the legs helps too
A falling cat can extend the legs and body to increase air resistance.
That can reduce falling speed somewhat and help stabilize orientation.
It does not make the fall harmless.
Can a cat survive any fall?
No.
Cats can suffer severe or fatal injuries from falls.
The righting reflex only helps orientation.
It does not cancel gravity or eliminate impact.
Windows and balconies remain real hazards.
Why can very short falls be dangerous?
A cat needs time to sense orientation and complete the righting movement.
In a very short fall, there may not be enough time to get the feet underneath the body.
What about very high falls?
Some cats survive surprisingly high falls, but survival depends on many factors.
That fact should never be turned into the idea that high falls are safe.
They are not.
So cats do have impressive midair control.
They do not have an unlimited supply of extra lives.
A related animal question is Why do cats like boxes?, which shows another way biology shapes familiar behavior or anatomy.
And that’s the short explanation.
Related explanations: Why do cats like boxes?, Why do cats have whiskers?, and Why are cats’ tongues so rough?