Cats sticking to each other, also known as pressing or rubbing, is a common form of communication. This behavior is often considered a cat's way of communicating friendship, intimacy, or social interaction. Cats post for many reasons, some of which may be to communicate affection or to build social bonds. Sticking may also be an exchange of scent information, as cats use their sense of smell to learn about the world around them. Sticking may also be done to apply one's scent to mark one's territory in the surrounding area.
In addition, sticking to each other may also be a self-protection mechanism for cats. When cats feel threatened or upset, they may stick to express relief and safety. In summary, sticking is a common form of communication in cats, and it can be for many different reasons. Their bonding behavior helps cats better understand and connect with their surroundings and other animals.