There are probably few smells worse than that of a decomposing rodent. After a rat dies, the body begins to break down, releasing a combination of methane, sulfur dioxide, hydrocarbons and benzene derivatives into the air that creates the unpleasant smell. Sometimes the carcass is difficult to locate, or in an area where it cannot be removed by the homeowner. Even if it is removable, the odor can linger for weeks. However, with a bit of persistence, there are several methods for getting rid of the unpleasant stench.
Things You'll Need
White vinegar or bleach
Liquid masking agent, odor neutralizer or disinfectant with movable spray tip
Misting or fogging machine (available online or in home improvement stores)
Find and remove the carcass of the dead rat, as it will continue to smell until it has completely dried out. Use rubber gloves to place the body into a plastic bag, sealing tightly before placing the carcass in the garbage. Scrub or spray the area where the carcass was found with vinegar or bleach.
Drill a hole into the wall approximately 12 inches above the floor, if the carcass is in a wall. Using a spray tip that can moved in all directions, spray the chosen disinfectant, masking solution or odor neutralizer into the hole. Reseal the hole in the wall with the hole filler.
Ventilate the affected area immediately, using one or several fans to force fresh air into the area.
Spray the masking agent or odor neutralizer into the air with a misting or fogging machine, if the rat carcass cannot be located. This will immediately neutralize the odor, but will require repeat applications until the carcass has completely decomposed.
Run an air purifier that uses an absorbent filter with either silica gel or charcoal. As air circles through the filter, it will trap odor-causing particles.
If the rat has died in the wall or ceiling, it might cause a stain or damp spot; it might also be found by looking for flies or maggots in the area of the smell. If you need to drill a hole into the wall to neutralize the dead rat odor, spray the solution on either side of the carcass in the wall for additional odor coverage.
Be cautious about claims for deodorizing or ionizing devices to remove odors. Ozone generators are a concern to the Environmental Protection Agency, and ionizing devices have not been scientifically proven to work on this type of odor.