Mouthing / biting

Question
Four weeks ago I adopted a 4month old pit bull terrier boxer mix from SPCA.  The dog had been surrended - we do not know why.  Generally she is a good dog - she does listen a little bit and we do use training treats for sit / stay etc and she responds.  She does have an issue with biting and at times bites with some aggression.  We have tried numerous things that are not working: walk away when she nips or bites and say "no bite"/ redirecting to toy / high pitched "ouch" and none of these are working.  When she gets really rambunctious ( even after long walks and playtime) every night - she shows a little aggression and jumps all over the kids and I and bites and when I try to calm her down or get her off the bed she really bites me hard.  I ended up yelling and screaming which of course does nothing.  We give her a time out in her crate for a few minutes and sometimes it works - but I know that isn't a solution.  Also this dog does not seem to care when you take away your attention - she doesnt seem to necessarily want attention that much.  I'm really having a hard time.  Also I'm taking training classes for her and the trainer suggested things we have already tried.  Somtimes when I'm corrected a bad behaviour she nips or snaps. Any light you can shed is appreciated.  Thanks, Karen

Answer
Nipping and biting is normal behavior for puppies. Using time-outs and letting her know that she hurts you is fine, but try to stop play before she gets to that point.  

Avoid confrontations on the bed by not allowing her up there.  Close bedroom doors.

You don't say how old your kids are, but she shouldn't be allowed to play with toddlers at all.  Older kids can follow your directions and stand still when the puppy gets too excited.  Use baby gates, exercise pens and crates as needed to keep her separated from small children.

If you recognize a certain time each night that she gets riled up, have a plan on keeping her occupied doing something else - a puzzle toy, a great chewie - like a bully stick, or plan some training for that time.

Be sure the dog is getting enough physical excercise during the day.  This is usually the cause of hyperactivity during the evening.  Find a day care that has special groups for puppies, or network with others in your training class for play dates.  

Please check out these sites on puppy biting:

http://www.shirleychong.com/keepers/archives/bite.txt
http://www.youtube.com/watch?v=c77--cCHPyU (instead of clicking, say "yes!")

Hopefully your trainer is using positive reinforcement techniques and not encouraging you to physically correct the dog for biting.  That will only make the problem worse.  

Here's where to find good training in your area:

http://www.karenpryoracademy.com/find-a-trainer
http://positively.com/dog-training/trainersearch/
http://www.ccpdt.org/
http://www.apdt.com/petowners/ts/default.aspx
http://iaabc.org/consultants

Please let me know if you have further questions or comments or need clarification on anything I've recommended.  Good luck!