KC was never really a "kneader" but Shermie does it a lot on the bed's comforter. It's very soft and feels almost velvety; this is the only thing he does it on. Usually at night he'll come onto the bed and instead of laying down to sleep, he'll start kneading on the covers, purring, and drooling - a LOT. Is this a normal thing? I know that lots of cats knead on things but do they all drool this much? And I was just curious why cats even knead in the first place. I heard somewhere that it reminds them of their mothers. True?