I had believed that the answer to the question, “Why do cats knead?” was well known. But a keyword search tells me that there are few websites answering this exact question. But I may and probably am wrong!
Kneading is when our cat or kitten tramples on our lap with his or her front paws. Most if not all cat owners have experienced this or should have. If your cat is not a lap cat (and mine isn’t) then the kneading won’t take place on your lap but will probably happen on an item of your clothing or say a blanket; usually items that need washing! The items of clothing can be quite intimate and sometimes it can lead to wrestling with it and chewing it. I remember a Bengal cat breeder mentioning this. The Bengal is a little more energetic!
The cat in the video seems to be trying to actually suckle at the nipple going a stage further than just kneading
If a cat kneads your lap it seems to usually happen soon after arriving and settling down on your lap. Your cat will press down with one front paw then the other. The claws extend slightly and grasp the knee (the bit we can feel but which we must accept). The action is rhythmical and almost seems to be in slow motion at one stroke every two seconds. And it can be accompanied by drooling (from the cat, of course!) and purring.
I think we know that this tender encounter (albeit a bit prickly) originates in early kittenhood. When at her mother’s nipple the kitten stimulates milk flow by “milk treading”.
The reason why your now adult cat is milk treading for milk from your knee is because when you sit down in a nice calm environment, your cat, who is in a state of perpetual kittenhood in her relationship with you, perceives this as an invitation to feed. You (the cat’s mother) is saying, “I am ready to feed you my sweet little kitten…”. This signal to feed is reinforced by the fact that we are the sole provider of food, including milk sometimes (special cat milk only please).
As this is one of the closest and most tender moments between cat and mother (and we are the mother, let us remember) it really must be accepted and indeed enjoyed. We certainly must not push or shove our cat off our lap or worse, slap him or her. We are obliged to reciprocate and be tender and loving thus binding the relationship and bonding more with our cat. Come on — we can get used it with bit of perseverance and love!
From Why Do Cats Knead to Why Do Cats
Why Do Cats Knead