Dogs curl up into a ball because of the cold, so that the body’s heat dissipation area is minimal, which is conducive to warmth, it is not too cold. Especially in the winter time, dogs prefer to stay in a curled up position so that the body temperature is easier to go up. Sometimes the dog sleeps in a huddled mass, possibly because of distrust of the owner, or the dog has just changed to an environment he is not familiar with. Such a posture is a defensive posture for unfamiliar environments, strangers, and when shrinking into a ball, the dog will feel safe.
