There could be several reasons why a mother dog may move away from her puppies. One common reason is to regulate the puppies' body temperature. Newborn puppies can't regulate their body temperature effectively, so the mother may move away to provide them with a cooler or warmer spot. Some mother dogs may feel anxious or overwhelmed by their puppies and choose to distance themselves temporarily. It's also possible that the mother dog is experiencing health issues or discomfort, which may cause her to avoid contact with her puppies.