Something to think about might be putting up some sort of see-thru netting in front of the crawl space. I guess it depends on how big the opening is. That way it would still be venilated yet no animals would be able to go in there. Also for the stentch there's a very strong spray you can buy that neutralizes the air. I forget the name of it right now, but one spray does the job. My old roommate used to use it all of the time. I think she got it at like Wal-Mart in the automotive department actually. I used to complain about her smoking, and after she would spray that, I couldn't smell it at all.
~Jill
