My 6 month old shih-poo gets crazy hyper everytime someone enters the room. Weird thing is, he'll jump on you (okay that's the normal part) but he'll then start digging and nibbling at my feet? Why does he do that? How do I teach him to stop biting? I know he is still somewhat of a puppy but will his puppy biting ever stop? And why does he love feet so much??