We've all seen cats kneading (a.k.a. making biscuits) like busy little bakers--their paws alternately pumping back and forth upon soft, "doughy" items like blankets, pillows, furniture, plush toys, other animals, and, of course, people. Almost all adult cats knead, and they all appear to have their own kneading style. Some knead with all four paws, others with just their front two. Some purr, some are silent, and some (like my Lynx Point Siamese, Riley), are given to drooling. No matter how it's done, a biscuit-making cat is adorable to behold, unless of course the cat happens to be kneading on YOU and he's fond of using his claws (ouch!). If you're curious as to what the experts have to say about cat kneading, then read on!
The Need to Knead
The most commonly-stated reason for kneading is that it's a kitten behavior that gets carried over into adulthood. Kittens knead on their mothers during suckling--an action thought to facilitate milk flow. Indeed, some adult cats also suckle the object that they're kneading (blanket, pillow, etc), oftentimes purring loudly and working themselves into a seemingly blissful, zen-like state.
Kneading Makes Scents
Another reason that cats knead is that it allows them to mark objects with their own unique scent. Felines are equipped with scent glands in their paw pads, and these glands secrete pheremones allowing them to stake their claim on things (and people) that belong within their territory. Marking familiar objects, spaces, and others (and then later recognizing what they've marked) helps to instill cats with a sense of well-being, safety, and contentment. So, whenever your cat kneads on you, consider it a huge (if painful) compliment. Since this is natural instinctive behavior, never discipline your cat for kneading. Whenever one of my cats starts a kneading session on me, I reach for a thick blanket or cushion to put between me and those claws!
The Heat Is On
If you've got an unspayed female cat, you may notice that she has the tendency to knead more than usual right before going into heat. Increased kneading in female cats in heat may be a way for them to signal to male cats that they're ready and willing to mate. Along with loud wailing, urine marking, and restless pacing, kneading is just another perfectly natural symptom associated with feline estrus.
Making Biscuits or Making Their Beds?
Another theory about cat kneading is that they are physically "preparing" a place for themselves to nap or, if they're carrying a litter, to give birth. Just like dogs will instinctively perform a digging motion in their doggie beds, sofas, pillows, and blankets in order to dig themselves a comfy "den" (as they would have done in the wild), cat kneading may serve a similar purpose. In the wild, cats would flatten out tufts of grass, leaves, dirt, etc. in order to make themselves a nice, level place to lie--which means that kneading may also serve this very practical purpose.