The puppy needs to get lots of attention and play time with its human family. One of the things that puppies do a lot of is jumping up on people and pawing at them. If you have children, you will need to be all the more diligent in training of the puppy to ensure that the playful pup doesn't accidentally injure the children. This is another reason that your puppy needs to get into obedience training immediately. Finally, there is the mouthing.
Puppies have a habit of wandering about with their mouths open.
They jump and play with their mouths open. The put their mouths on and around everything, including your hands. They will grab your pants legs as you walk by in their teeth. They will jump up and grab your sleeve. They will come running up to you, jump into your lap, and whip their little heads around in joy with their mouths open, sometimes clipping you with the exposed teeth.