In English, we call it making biscuits. In Japan, a cat is kneading the dough for udon noodles. This kneading motion is leftover from when kittens stimulate their mother's milk while nursing. As adults, it may be a way to show contentment, to calm down, or to mark their territory.
Despite becoming famous for getting into boxes, Maru has been "making udon noodles" for years now. He has a very particular way of doing it. He always has to have something in his mouth, so his human, mugumogu, provides him with plenty of objects to serve as a pacifier. He uses all four paws and also puts on a very intense stare. This compilation ends with Maru showing off his finished bowl of udon noodles... and then getting back to work making more. -via Fark