From an email written to a past landlord:
The past couple of days, I've been noticing an unpleasant smell in the living room area. I couldn't figure out what it was, since there's nothing in there but the usual things, but I think I may have figured it out. It seems like there might have been an animal underneath the house that died and that's what the smell must be--it's a familiar one, and only really strong in one part of the room. Anyway, I don't know if there's anything that can really be done except wait for it to go away, but I wanted to let you know that I do think there have been some kind of animals beneath the house. Occasionally, I've heard loud scratching/hissing coming from underneath the bathroom tub. Did previous residents ever mention this? Well, I know that's a bit unsavory, but thought you might like to be aware.
Thanks a lot and hope you are having a nice weekend.