I have a 7 week old red nose pitbull pup who wont stop biting. I got her when she was exactly 6 weeks. I did some research and i found out that in between the 6 and 8 weeks time period they learn the pain tolerance that other puppy siblings can handle, but she is no longer around her siblings. A couple days after i got her she started nipping. It was fine at first because it did not hurt but it has become a problem. She has a rope ball, kong toy, rope, and a rubber flip flop to chew on but none of them amuse her for no more then 2 minutes. When she goes outside the likes to chew on the side of steps, tree branches, and plant stems but after that she comes to nip at my toes ankles and fingers. She also likes to bite clothes and tug on them as if it is a game of tug of war. The yelping and ignoring method , the crossing arms and yelping method, the replacing with a toy, and the two finger tap method do not work. I understand she loves to play but the biting is unacceptable. Today she has bitten me three times all of them left marks and 1 of them has caused bleeding. She is a good puppy but her biting is a big problem. PLEASE HELP!!!!!!!!!