Puppies play puppy games, not human games, with humans…And puppies in a litter play games such as wrestling, biting, chasing, tug-of-war, and keep away, until we teach him some others.
Also, dogs and humans, despite our closeness and mutual affection, often miscommunicate. Children, particularly, routinely mishandle puppies, not realizing it, and are at risk of being nipped or even bitten (especially when they play puppy’s favorite game of “chase” for instance! )
It sounds weird, but to avoid lots of “hitting” on the nose or yelling, when your pup bites down on you or your child’s finger, take a finger with no nail, and stick it far down his throat to trigger his gag reflex. It is humane, yet uncomfortable enough that puppy will think twice next time! Make sure the whole family is consistent with all training methods; otherwise puppy will learn to respect only the one who carries through with discipline!
Sometimes puppies who are stressed by isolation , boredom, and lack of exercise are even more likely to be mouthy, so do ensure that you are meeting your puppy’s basic needs.
Besides the above method of “gagging” consistently until pup decides he does not like the uncomfortable surprise, you can try the “tree method”. When pup bites, say OW!!! loudly, then immediately turn away from puppy, tuck your hands under your arms, look up at the sky and ignore for 30 sec. Or until puppy stops any bite attempts. Then turn to puppy and have him run through two or three obedience commands and reward him. After many repetitions, your puppy will get the picture: if he bites, he loses his playmate. Teach pup to also play alternate games that he can exercise and learn attention without being touched or tempted (retrieving, hide and seek)
I’ve never had a puppy NOT respond to consistent correction for play biting, so I’m sure this will pass once you have tried the above.
Good luck!