Cats sleep rolled up into a ball, which minimizes the heat dissipation area of ​​the body and helps keep them warm and prevents them from getting too cold. In the process of continuous evolution, cats gradually form this habit to better adapt to the natural environment. Especially in winter, cats prefer to stay in a huddled position, so that their body temperature can rise more easily.

Sometimes cats curl up in a ball to sleep. It may be because they do not trust their owners, or the cat has just changed to an unfamiliar environment. This posture is a defensive posture against unfamiliar environments and strangers. When curling up into a ball, the cat will feel a sense of security.