Eliminate the odor of dead mice in the walls by using ground coffee, an absorbent odor-removing bag or an electric air ionizer. Another option to help get rid of the smell of dead mice in walls is to use a bio-enzymatic spray odor eliminator.
One way to eliminate the odor of dead mice in walls is to use coffee grounds to absorb the scent. This is not the most effective way to take care of the problem, but it works until you find a better solution. Place the coffee grounds in air conditioning vents, cabinets, basement corners and in any area from which the smell seems to be emanating.
Another option to help get rid of the smell of dead mice in the walls is to use an absorbent odor- removing bag, such as Earth Care Odor Removing Bags, which consist of a special blend of minerals designed to absorb rotting carcass odors as well as the smell of mildew, smoke and skunks. This method works best for those who are able to pinpoint exactly where the rodent's corpse is inside the walls. Hang the bag in the affected room, and lock the door. The odor begins to decrease within hours and disappears completely in the next few days or week. One of these bags covers 100 square feet of space.
An air ionizer is also helpful for getting rid of the smell of dead mice as well as purifying the air. Even if the ionizer doesn't totally eliminate the smell, it kills any harmful viruses, bacteria, germs or microbes that the corpse may produce.