https://youtu.be/Kl2UxxGNcmg
Some home pest control procedures can lead to concealed bodies that are only recognized by the smells they discharge as they begin to decompose. Obviously, identify the source of the stench is most important and then disposing of it. Dead rodents are often located within walls or rafters. If this happens, it may be necessary to suffer the smell until it disperses on its own. The time it takes for the rodent to decompose depends on many factors, including size of the rodent, temperature, humidity and accessibility to decomposers like flies. Unfortunately it may take a week or up to 5 weeks to completely decompose. If you are able to find the source, the unsettling scent may linger for a while longer. Opening windows and using electric fans may help remove the smell and expedite the process. Deodorizing air fresheners, such as Ona products and disinfectants can also help to eradicate smells. Were gloves and a respirator while cleaning any contaminated areas, as rodents are known carriers of a multitude of diseases.
http://www.delta-optimist.com/opinion/blogs/deltabc-1.983313/blog-oh-that-dead-rodent-smell-1.2153456