What behavior do sled dogs exhibit at night for sleeping?

In "The Call of the Wild," sled dogs exhibit the behavior of burrowing under the snow for sleeping at night. This instinctual behavior helps them stay warm and protected from the harsh cold of their environment. By burrowing, they create a sheltered space that minimizes heat loss and adds a layer of insulation against the bitter elements. This adaptation is crucial for their survival in the frigid conditions they face while pulling sleds in the wilderness.

Each option represents different ways that animals or sled dogs might find comfort, but burrowing specifically highlights a survival strategy unique to their environment during extreme cold, illustrating their natural instincts and the ways they adapt to their surroundings.