Kneading is a behavior frequently observed in domestic cats where, when a cat feels at ease, it may push out and pull in its front paws against a surface such as furniture or carpet, often alternating between right and left limbs). It is also referred to as "making biscuits" or "baking" because the action is like kneading dough. Many theories exist that explain why cats knead. One theory is that kneading may 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. Another theory is that the behavior may be a remnant of a newborns kneading of the mothers teat to stimulate milk secretion. Kneading may also be a form of communication between owner and feline, as the behavior may be a communication of affection towards the cats human companion). Many cats purr while kneading, and they also purr mostly when newborn, when feeding, or when trying to feed on their mothers teat). Cats have scent glands in their paws that release pheromones when the paw stretches with the claws out. Since kneading involves a grasping action where the claws extend briefly, the theory is that kneading is one way cats mark their territory.