I have posted before about Tilly chasing cars, and some of you didn't like the way I was training her to stop doing it.  You will like that I now use a tuna fish can filled with pebbles, covered with duct tape and take that to shake whenever we are out.  She hates the can shaking,so she doesn't chase.  She is getting a lot better.  I also use this can when I don't want her to bark.  But the next problem that I have with Tilly, now just short of 8 months old, is that when I open the downstairs sliding doors, she attacks them, barking up a frenzy and biting the door.  Sometimes she just wants out so that she can attack the door. She gets frantic about it.  Not sure why she doesn't attack the door from the inside, just on the outside.  If I or Abby my Golden Retriever step through the door when she is already out, she'll be so agitated/excited from the moving sliding door that she will try to bite us!  She doesn't break the skin, but has come very close and it hurts a lot.  Abby is afraid to go out the door when Tilly is outside already.  I've tried opening the door ever so slowly and it is better, but this is not real life.  I have tried brushing chili pepper sauce on the door where she often bites it.  I don't think she liked that, but still continued to attack the door. I have also shaken the can at her, but it makes no difference.  Has anyone else had this problem, and please, please tell me what you did to solve the problem.