When buck wanted to sleep, what did he learn to do from the other dogs and why?

Buck must learn the proper way for dogs to sleep. Initially Buck sees the bright lights in the tent of François and Perrault. He remembers sleeping by the light of the Judge's fireplace and approaches the tent. Buck is met with curses and cowers back to the snow. Buck learns, from other dogs, that he needs to burry himself in the snow. The snow, combined with his coat, acts as insulation for the cold winter nights.