Oh yes, the brat stage, ug, Hershey did this same thing. I hated the brat stage, he liked to chew on arms too. A little over 12 weeks is when they aren't that calm cute little puppy anymore, run, run far away! (yes, they are still cute!) hehe. Just not the calm cute anymore. The brat stage of puppyhood. Learn to love it, because she won't be there long. (the calm stage) lol, but, you have gotten great advice, sorry I am never any help. But I wish you luck! so does Hershey. Your doing a great job, just keep constant training, and you will do great!