Wow, I'm surprised about Jack. He is a high-energy boy, but he's so smart & clever, and seems to really enjoy attention from people, it's hard to imagine he'd actually bite a person. I hope things work out alright for him. Youv'e taught him so many cool tricks, maybe you can teach him to keep his mouth shut? Oh, wait a minute, that doesn't work with kids, either.
Just joking, I know it's a serious issue.