Puppies spend most of their time sleeping and feeding. With their litter-mates, they pile into a heap and if they are separated from them they become distressed even in short distances. Even if they can’t open their eyes when they were born, their sense of smell are fully functional.
Puppies are sociable animals. They develop social skills around people when they socialize with humans. Those puppies that are not socially exposed to humans during their ages of eight to twelve weeks may develop fearful behavior around humans or as adult dogs.