Why do dogs curl up in a ball when they sleep

If you want to know why the dogs curl up in a ball when they sleep, Then this video is the perfect video for you.
When dogs sleep, they will dig a shallower hole in the ground and curl up especially when outside, in the wild, especially in colder areas.
This provides them with warmth, and when we curl up in this way, the body maintains its temperature more easily. Also, in that position, the most sensitive internal organs are protected from the sudden attack of predators.
Dogs sleep in this position and in the house, in a safe place, although they are not in any danger. It sounds ridiculous, but it is a reasonable tactic inherited from distant ancestors.