A dead rat trapped in one of your walls or somewhere else in the house, leaves behind a foul and abrasive odour. The longer you leave the dead animal carcase in the house, the worse the smell becomes. As the body of the animal breaks down, the proteins in the body bloat and adhere to the surrounding areas. Even after the body is removed, the smell still lingers in the air. Cleaning the area removes the odour of the dead rat.
Locate the source of the smell, finding the location of the dead rat. Remove the body, using a shovel or wearing rubber gloves on your hands. Toss the body into a garbage bag or an odour-eliminating bag and remove it completely from the house.
Spray an odour neutraliser into the room or space where you found the dead rat. Traditional air fresheners spray a scented liquid into the air, which only covers the smell for a short period of time. An odour neutraliser actually breaks down the odorous smell in the air.
Fill a small bowl with vinegar, either apple cider vinegar or distilled white vinegar and place in the room. Fill a second bowl with baking soda and place on the other side of the room. Soak a cotton ball in vanilla extract and place in the baking soda bowl.
Clean the floor that the dead rat touched with liquid bleach. If you're worried about the bleach damaging the flooring, use a diluted form, with ¼ cup bleach mixed into one gallon cool water. Wipe down the floor with the mixture and then wipe again with fresh water.
Apply bleach or a diluted bleach mixture to the walls. Let the bleach sit on the walls for five to 10 minutes and then wipe off with a towel or cloth dipped in fresh water. The bleach destroys the odour molecules, making the area smell fresh again.
Be careful using bleach around the house, as it can discolour the walls and floors.