Puppies are really loyal and cute.

At first, puppies spend the large majority of their time sleeping and the rest feeding. They instinctively pile together into a heap, and become distressed if separated from physical contact with their littermates by even a short distance.[5]

Puppies are born with a fully functional sense of smell. They are unable to open their eyes. During their first two weeks, a puppy's senses all develop rapidly. During this stage the nose is the primary sense organ used by puppies to find their mother's teats, and to locate their littermates, if they become separated by a short distance. Puppies open their eyes about nine to eleven days following birth. At first, their retinas are poorly developed and their vision is poor. Puppies are not able to see as well as adult dogs. In addition, puppies' ears remain sealed until about thirteen to seventeen days after birth, after which they respond more actively to sounds. Between two and four weeks old, puppies usually begin to growl, bite, wag their tails, and bark.[6]

Puppies develop very quickly during their first three months, particularly after their eyes and ears open and they are no longer completely dependent on their mother. Their coordination and strength improve, they spar with their littermates, and begin to explore the world outside the nest. They play wrestling, chase, dominance, and tug-of-war games.

File:Puppiesplaying-tokyoarea-jan7-2020.webmPlay media
A puppy Chihuahua (right) and puppy Toy Poodle playing in a Tokyo pet store, 2020
Socialization
Puppies are highly social animals and spend most of their waking hours interacting with either their mother or littermates. When puppies are socialized with humans, particularly between the ages of eight and twelve weeks, they develop social skills around people. Those that do not receive adequate socialization during this period may display fearful behavior around humans or other dogs as adults. The optimum period for socialisation is between eight and twelve weeks; professional animal trainers and the American Kennel Club advise puppies should be introduced to "100 People by 12 Weeks" and have encountered a wide and varied selection of people and environments.[7]

Docking and declawing
The practice of docking began primarily as a preventive measure for injury among working dogs. Docking is now primarily performed for purely cosmetic reasons, and some breeds traditionally have their tails cropped anywhere from slightly to almost entirely.[8] Many countries now ban cropping and docking for cosmetic purposes, including Australia, parts of Canada, the majority of the European countries (Austria, Greece, Finland, Netherlands, Italy, the Czech Republic, Turkey, Poland, Slovakia, England, Scotland, Slovenia, Ireland, Norway and Sweden), while others, such as the United States, permit it. As of 2008, the practice is opposed by the American Veterinary Medical Association.[9] Some breeders also prefer to declaw the dogs to prevent future injuries caused by scratching, or in the case of dewclaws, ingrown and ripped-off nails. Docking and declawing procedures are usually performed within the first few days after birth, by a veterinarian, or by an experienced breeder.