 This is instinctive to kittens and adults, and is presumably derived from the action used to stimulate milk let-down by the mother during nursing.Kittens "knead" the breast while suckling, using the forelimbs one at a time in an alternating pattern to push against the mammary glands to stimulate lactation in the mother.Kneading may also have an origin going back to cats' wild ancestors who had to tread down grass or foliage to make a temporary nest in which to rest.