The short answer is because it’s fun. But play serves a number of important roles.

Puppies need to learn to be dogs. While there’s a lot we still don’t understand about play, it seems that play is important for learning both social skills (how to behave with other dogs) and motor skills (how to move their bodies) (Sommerville et al, 2017). Play can help puppies learn how to deal with unexpected things happening such as when they get knocked over. In turn this can help them regulate their stress response when tricky things happen, so that they are more resilient.

The social skills learned in puppy play help them to have good social relationships with other dogs when they are older. This actually applies to their relationship with us, too; when dogs play with their guardian it helps to build a stronger relationship.

One of the most important things puppies learn is bite inhibition. When playing with their littermates, if a puppy bites too hard the other pup will yelp and stop playing for a little while. The puppies will learn to be gentle with the jaws and teeth in order not to stop the play (Bekoff, 2001; Dietz et al 2016).