some small animal/rodent that is no longer living. The smell has been around in our kitchen/dining room for about a week, we've cleaned, sprayed, lit candles, plug in air freshners, checked drains etc. Until my DH noticed a air grate/grill at the back of house was open/off and he said the smell seemed to be coming from there but couldn't see anything (this would run under floor of house). So what do we do, who do we call, is it going to cost much?????