When you touch a cat's back, its arching of its body is usually a self-protective instinct, a fairly common feline behavior. This arching behavior may have several causes:
Pleasant Reaction : Some cats express their comfort and happiness by arching their backs. This arching is an active posture; they may rub against your hand or head to show affection.
Alertness and defense : In some situations, when cats feel nervous, fearful, or alert, they may arch their backs and their fur may stand on end. This is a way for cats to display a threatening posture, make themselves look bigger, and thus defend against potential threats.
Comfortable stretching : Sometimes cats arch their backs when they stretch, which is how they stretch their bodies to gain greater comfort.
To understand the specific reasons why a cat arches its back, it's necessary to analyze it in conjunction with other behaviors and the context. For example, if your cat arches its back while displaying a relaxed expression, raising its tail, and purring, it's likely because it feels happy and content. However, if the cat appears tense or its fur is standing on end when arching its back, it may be expressing anxiety or alertness.
