Puppy biting is a normal behavior for puppies, and it is a way for them to explore the world using their mouths. Puppies usually start to bite and mouth at around 2-3 weeks of age, and this behavior peaks when they are transitioning from baby teeth to adult teeth, around 12-13 weeks of age. Puppy biting usually subsides around 5-6 months of age, when all of their adult teeth are in, and they have learned to play with toys and appropriate chews. However, it is important to note that this timeline is not set in stone, and some puppies may continue to bite beyond this age.

It is important to manage puppy biting appropriately to prevent it from becoming a problem behavior. Physical punishment should be avoided, and instead, interactions should be managed carefully and actively supervised. Redirecting play biting and mouthing to appropriate toys and chews can also be helpful. Consistency is key, and all family members and guests should be consistent in their approach to managing puppy biting.

In summary, puppies usually stop biting and mouthing between 3-6 months of age, but this timeline can vary. Appropriate management and redirection of biting behavior can help prevent it from becoming a problem behavior.