when we first got Penny everything was fine but lately she's getting nippy. I've been bitten no blood or broken skin thank god. If I'm brushing her she gets nippy. If I walk amd my shoe laces are moving in any direction she has to charge at them and bite. Today I had to smack her a few times. I Know I know DON'T HIT The Dog. I'm sorry if I offend anyone by hitting a small puppy. I smacked her on her rump. Is it something I'm doing? Was if my fault that the reason she is getting nippy is because of the rough housing I do with her like Tug o war? Is there a way to correct this nippiness and growling? Several minutes ago I yelled NO to her and she seemed to understand what it meant. She stopped what she was doing which was jumping up to get out of where she is and went back into her crate. I'm frustrated and angry. She starts obedience training at PETCO tomorrow. Will this behavior go away as she leanrs her commands? Please Please Help me so that I can turn my puppy into a good dog.