Cats like to rub against people because of their territorial awareness. A cat’s territory refers to the space that ensures its food and safety. At the same time, it is also a “place where it can feel secure.” Because the cat is familiar with the terrain and routes, it can move freely, so it is a place that makes it feel at ease.

　　However, this degree of security is not the same everywhere within the territory. The place considered its own nest is the most reassuring — this is the central area of the territory. As you move away from the central area, the sense of security gradually decreases, and the farther you go towards the edges, the less secure it feels, with the outside of the territory becoming a place that causes anxiety. Therefore, unless there is an emergency, cats will not easily leave their territory.

　　In the places where cats feel safe, they emit their scent around, which they do by rubbing against objects. Because they smell their own scent, they feel reassured, and once they feel safe, they will rub against people repeatedly.

　　Cats have scent glands distributed on their cheeks, under the chin, and at the back of the head. Scratching these areas releases their scent. These spots are also places that are easy to get itchy. When tense, they may forget the itchiness, but once relaxed, they feel itchy and want to scratch. Moreover, to “scratch” these areas, wherever they rub, their scent is released. The more they feel safe in the central territory, the more they want to rub things, so the central area becomes an increasingly reassuring place.

　　The same applies to domestic cats; when relaxed, they rub against things nearby — which can be the corner of a cabinet, the leg of a chair, the edge of a wastebasket, or people. When rubbing against people, it feels like scratching an itch, so when you see a cat looking very relaxed and insecure, you want to scratch it as well. (Source：PetsZone)