Search: why do cats rub their faces on things
Why: I am trying to read a book, but Maddie keeps rubbing her lips on the corner of the pages.
Answer: Cats have pheromone glands in their foreheads, lips, front paws, flanks, and rears. They leave their scents on places and other animals (and people) to mark their territory, to communicate urgency (like hunger or danger), and to signal familiarity. The pheromones secreted by glands in the face seem to have a calming effect on cats.
The More You Know: When a kitty headbutts you, it's an affectionate gesture. Only cats that are completely comfortable with each other will engage in mutual headbutting, called bunting.