What's the deal? - Page 1

I've noticed that my girl's hair stands up on her hackles and tail when she sees others dogs and sometimes for no noticable reason ( no other animals around ) I am not sure if this is a sign of excitement or fear... Can anyone shed some light? Also I am afraid she lacks some confidence, I am starting her in obedience classes in Jan. but I was wondering if there was anything I can do to boost her confidence and help relax her a little. I say she lacks confidence because she will coware and tuck her tail whenever she meets people or other dogs. I could be mistaking it for submission...either way I don't like the behavior. Thank you.