Puppies begin to play as soon as they can walk. Littermates commonly wrestle and chase each other, pulling on ears or tails. Through play with littermates, pups learn just how strong they are or how to turn circumstances to their advantage.
 

By the time they are weaned, each pup has formed an impression of its own abilities and social standing within the ranks of littermates. This forms the basis for adult behaviour, such as achievement of dominance, in relation to people and other dogs.
 

Play allows a young animal to practice important life skills without adult consequences. Running, jumping, hiding and other playful antics could be invaluable later when hunting for food or escaping an enemy. Play is one of the best ways to teach desirable behaviour to a pet by setting standards for a lifetime. By tolerating subtle or not so subtle dominance behaviour even in young puppies, for example, you may encourage inappropriate social patterns.
 

Undesirable forms of play
 

Wild and uncontrolled forms of play frequently lead to undesirable behaviour in juvenile and adult dogs. Games that encourage chasing and jumping on people promote aggressiveness. Don't encourage your dog to mouth, chew, nip or nibble any article of clothing or part of a person's body, even if it is behaving playfully. Avoid games that arouse your dog's aggressive instincts, such as wrestling or tug of war with any object.
 

Forms of play that do not focus a dog's attention on your or reinforce your authority may lead to misdirection of the animal's energies. The results of a dog's unrestricted activity are often undesirable. Also, you lose the opportunity to teach your dog desirable skills.