Question: I think I have a dead animal in one of my walls. Is it a mouse? How long will it take to decompose? What can I do about it?
ANSWER: It could be a mouse. It will take about 2 weeks. It is usually difficult to remove them when they are inside a wall. A room deodorizer might help.
The only way to get rid of the carcass would have to be by cutting into the wall. This may be difficult, as the odor may permeate through the walls and it is hard to localize the exact point to cut the wall.
Oftentimes, this can be a result of do-it-yourself pest control where someone with a rodent problem goes to the local hardware store and purchases some bait. After consuming the bait, the rodent dies in the wall, and then you have to live with the odor for at least two weeks.
Instead of doing it yourself, let an expert do the job. If you have a rodent problem, call the local Orkin Branch Office and ask to have a highly trained Orkin Pest Specialist come to your home, inspect and assess the problem. The Orkin Pest Specialist will develop a customized treatment plan, based on the science of rodent control, that fits your needs and will include recommendations to keep your home rodent free.
Additional information about getting rid of mice in the home can be found here
The Orkin Man used the information above to also answer the following questions submitted by Orkin.com users:
Question: I think I have a dead mouse or rodent in the wall or ceiling or possibly in the heating duct work in the house? What should I do?
Question: How to get rid of mice that are in the walls, and how much does it cost?
Question: A foul odor was noted in our storage room. I suspect a dead mouse. What do you suggest for removal of odors? I can’t locate the source. How long will the smell last?
ANSWER: The odor will last about 10 days or perhaps a bit longer. There is no certain way that the dead mouse can be found, and there are no chemicals that will take the odor away. Mouse baits may be effective, but often the mouse dies behind the wall and there is a lingering odor for several weeks, this is why use of rodent baits indoors is not a recommended course of action.