In addition to dead animals trapped within attics and walls, possible sources of bad odors inside a home include rotting food, mold and refrigerator pan drippings. Clogged sink pipes can also cause unpleasant household smells that resemble the odor of dead animals.
Wildlife poses a common cause of bad household odors. Squirrels, feral cats, raccoons, rats and other small animals can become trapped in attics, basements or walls, especially during cold weather. Unable to find their way out, the animals die. Their carcasses rot and release unpleasant odors that can make a house virtually uninhabitable. A qualified nuisance wildlife operator can locate the dead animal and remove it.