Interesting! It's possible they do smell pretty different from us. My 17-year-old nephew is living with us at the moment and rarely opens his window to air his room. I go in sometimes while he is out to open the window because it really does need it. And when my sister came to visit, the first thing she noticed was the smell in his room and the need to air it (she actually thought one of the cats might have peed in it but I am certain they hadn't).

Yeah, I'm not too keen on bad smells either. I hear you, Susie :)