I am renting a duplex. I have been fighting off rats since I moved in. There are dogs next door in the adjoining duplex. (they are always outside). I am sure the dog food is a big attraction. In addition they have thrown HAY down for the dogs to sleep on. They also have several cats that they put food down for. I have one indoor cat. She only gets what she can eat and the food is sealed. My landlord removed three very large rats from under the house. They are there for the heat. Also there was a large hole in the lundry room floor and the dryer hose was venting into the underground. Rats were getting in. My landlord fixed that problem. Now I have a smell that is making me very ill. How sick can that make me? Now that the rats are removed (and I keep my heat off... it's 40* out) the smell is OK. As soon as my heat is turned on the smell is strong in all of my heat ducts. Why? Thanks, patticake4u

Sounds like you've got a dead rat stuck somewhere in the duct work of the heating system. Most likley in the cold air return. As the air heats up in the system it makes the dead carcuss smell worse, just like a roadkill on the street on a hot summer day.

Your landlord should be able to assist you with locating the animal, or the source of the smell.

Very true, the smell depending on the size of the rat should be gone in about a week. That is the normal time it takes a rats carcus to start decaying.

More then likely the smell of the decaying carcass will eventually go away. If not you may want to ask your landlord to get the ducts cleaned professionally.

Once a friend of mine had that same problem in a large house. He searched for the carcass for a couple of weeks and found a lot( like 10 - 12) in the return duct right outside the unit. After cleaning that out the smell was gone in about 48 hours. I helped him clean that out and I will promise you you don't know what "stink" is.