How do cats move so stealthily?

Even though cats have four legs, when they walk, they leave what look like single file prints- one line of prints — not two, one right in line with the others.

Cats are capable of walking very precisely because, like all felines, they directly register; that is, they place each hind paw (almost) directly in the print of the corresponding fore paw, minimizing noise and visible tracks. This also provides sure footing for their hind paws when they navigate rough terrain.

Direct registering also serves a useful purpose — animals that stalk their prey can see where they place their front feet, so they don’t break twigs or make other noises. Then they place their hind feet in the exact spot, so they can move silently from place to place. Cats will show perfect registering; dogs however, have lost their ability to register.

The camel and the giraffe are the only other animals that move in this way. Other four-legged animals move the left front leg at the same time as the right hind leg, and their right front leg with the left hind leg.

Edit:
Since I wrote this story, I have adopted a cat. Meet Shuri.