Thanks for all of your replys--I think I have located the problem--but really not sure how to fix it. I ended up pulling all of the carpet up in the living room (which it needed it anyway), but that wasn't the problem, however some of the smell disappeared. My fiance had to end up going under the house to fix a slight water leak and the smell was extremely bad smelling under there. Well to put a long story short, this morning I noticed a large tom cat coming out from under the house. He had gotten under there since the crawl space cover wasn't on yet. Anyway, I am pretty sure that the smell is male cat spray and it is very strong under the house and is coming up into the house. Is there anyway to get the smell out from under the house or will it eventually go away on its own??? The crawl space is now covered and there is no way they can get back under there again. Thanks for the help.