Ok guys...there have been a lot of great responses...thank you. As far as trying to dominating me...I don't think so. Because we'll Be petting him, and he'll get a little hyper, and just slide the thumb nibble for litterally 2 seconds and let go. No pressure. Just kinda like how a baby would chew on something. He's very good. His previous owner put in alot of time. He in no way tries to dominate. He listens very well. I do have a concern though. When he meets new people he likes to jump, and harass for attention. How do I break this. Some people enjoy it, and others find it annoying. I don't mind with me, because I know he just wants attention. But as far as others I'd like him to calm down. My wife has a 4.5 y/o APBT, and he still nibbles. I've been reading and i've found that it's like them saying "I love you". I don't think he would ever bite in anger or defiance.