Hi Rox,
My female lab (Roxy!) is about 4 months old now, and she's brill. My only real problem with her is that she nips my son, who's 8. She rarely does it to my wife and almost never to me, but when my son is playing with her, he usually gets down to her level, i.e. on the floor, or else he lets her chase him or whatever. I'm sure there's no malice in it, she normally goes for his pants, but she has occasionally given him a scrape on the hand. Even if she's on her back getting tickled, all I have to do is grab a paw and the teeth come out. She won't go to bite me straight away but the intent is lurking there somewhere.
We're getting conflicting advice from "she'll grow out of it" to "don't tolerate it at all". At the moment, if I'm around, I keep a close eye on them and try to encourage the boy to stay on his feet and so on. If Roxy's teeth come out, I chuck her outside or give her a shove away or something but I'd rather not do the negative stuff. She had a problem with other dogs for a while (the first dog she met bit her) but we took her to puppy socialisation classes and now she's great. The puppy trainer told us that when she nips, we have to yelp, stand up and walk away.
Thing is, it's beginning to grate with me a bit. I'm tired of giving out to my son about it, and I'm sure he's tired of hearing me. I've had dogs for most of my life and can't ever remember any of them being this nippy (although rose tinted glasses and so on). Any advice?