While cats and dogs have some similar behaviors, there are a variety of behaviors we will only see cats do. For example, scratching, self-grooming, and face rubbing are common cat-only behaviors. A less common, but very special behavior we see is kneading.
Kneading, sometimes referred to as "making bread" because the motion resembles kneading dough, is the action cats do by pushing their front paws down and out on a soft surface. While alternating between paws, some cats will knead with claws out and some will knead with their claws relaxed. It seems to be most common for cats to stretch out their claws when kneading. The motion is usually a steady, rhythmic act, which is usually accompanied by purring and ends with a little cat nap.
Not only do cats have scent glands on their cheeks, they also have them on their paw pads. When they knead, the glands on their paws release their scent wherever they are pressing down. So when your cat is on your lap kneading your thighs, he or she is actually marking you as their territory.Instinctual
Cats actually start kneading when they are just tiny, little kittens. When newborn kittens are nursing, they will knead their mother's stomach to stimulate her milk production. This instinct likely follows them because cats might associate the act of kneading with getting a reward: milk.Stretching out
One of the reasons why cats love tall scratching posts so much is because they love to stretch out their joints and muscles. For example, if you don't have a tall enough scratching post and your cat is scratching your couch or wall, that might be the reason. Kneading is another way to stretch out different areas of their body and it feels good for them to do it.Nap time/Nesting
Cats like to sleep on comfortable surfaces. Cats' wild ancestors would knead down grasses or leaves to make a comfortable spot to lie down. Domestic cats today will do the same thing with their bed, a pile of laundry, or a blanket.Going into Heat
When female cats are just about ready to go into heat, they might knead a male cat to send signals that it is mating time.