All cats knead which can be painful when on your lap, but is an instinctive trait. Kneading is when a cat pushes its paws in and out, usually with claws extended. Cats purr while kneading, so it’s a pleasurable feeling for them. They knead soft surfaces like pillows, the sofa, your lap.
When newborns knead while nursing, it is thought to stimulate milk flow. One theory is that kneading can be a continuation of this behavior.
Since cats have scent glands in the pads of their feet, kneading releases the scent, marking the area. Kneading could be marking territory.
Female cats often knead before going into heat. In order to avoid this behavior as well as all the screeches and meows that accompany heat, it’s best to have your cat spayed.
Wild cats knead to make a soft bed of grass or leaves to lie in. Some pets knead before they go to sleep.
If kneading is annoying to you, keep your cat’s nails trimmed. Purchase a scratching post for your cat. You can also offer your cat a pillow you set aside for the occasion. This will help keep you and your clothing remain intact.
This behavior should never be punished.