There are two things worse than finding out a rat in your house: finding out a dead rat and not finding out a dead rat but smelling it from afar. I, personally, know exactly how a dead rat can smell; I can still bring the rotting odor back from my memory.
That is why in this guide you’ll learn: how the dead rat smells and how the odor is formed, different types of odor removal methods available on the market and which one of them is the most effective. By the end of the article we’ll cover TOP 5 powerful odor elimination methods that one day can come in handy!
There were two times I faced the dead rat smell problem: once in the attic and once from somewhere else, we didn’t even figure out where it was coming from. Both times the smell was absolutely horrific: it was like being in the epicenter of marsh gas fireworks.
I’ve never used the rat poison on my premises, but even without chemicals I still ended up with dead rats lying around my house. Unbelievable!
And if we were able to find the dead rat in the attic and quickly used an ionizer to get rid of the smell, we never found the second rat (presumably it was somewhere inside the wall) and had to wait for almost 4 week for the smell to eventually die down. While we were waiting for the decomposition odors to leave our house, the ionizer I used helped us greatly, thank Goodness!
Thanks to my background in biology I think I can claim a little bit more credibility than other internet sources on the subject, so I decided to write an article to help you get rid of the unpleasant smells faster and more efficiently. Because why not?
What does a dead rat smell like? How does the smell form and where it comes from?
The dead rat smell is composed of a mix of chemicals produced when the body decomposes, which begins at the moment of death.
The processes involving breaking down of tissues in the body release chemical compounds that are responsible for the unmistakable and toxic foul smell.
There are generally four stages of decomposition, in case you want to know the details, with accumulation of gases happening during the second (“bloat”) stage.
The built-up pressure of gases makes the bodily fluids escape the rotting corpse and enter the surrounding environment. The purging of fluids and gases results in powerfully strong odors. It is generally at this stage that you notice a characteristic foul smell in your household.
Unfortunately, if you fail to find the dead rat, the smells will continue until the rotting enters the final stages of decay with loss of remained tissues.
The duration of decomposition depends on many factors, such as exposure to water or air, temperature, oxygen availability, cause of death, body size and weight, humidity, the surface on which the dead rat rests. So if the rat is stuck somewhere inside a vent or wall, it may take longer for the body to decompose. The rotting and the odor may last for up to several months!
How do adsorbents and other types of odor removal methods work?
Hold your horses, the science comes to your rescue! There are smell absorbents available and other types of odor abatements that each works differently.
So how does the odor abatement work? Since an odor is essentially a compound of various chemical substances, its chemical nature can be changed to make it less odorous, completely odorless or neutralized for the human nose.
The basic odor abatement treatments include: airing the premises, cleaning, adsorbing and absorbing, neutralizing odor and deodorizing air.
Adsorbents & Absorbents
Adsorbents, like porous activated carbon or other adsorbent media, catch and trap the foul odor molecules as they travel through it. Clean air is released while trapped molecules stay in pores of the adsorbent.
It may seem like a great and eco-friendly option of eliminating foul odor. However, the effectiveness of adsorbents greatly diminishes over time. To continue using the absorbent, you will have to clean, re-activate, or replace it with a new one.
The most popular and well-known adsorbents are charcoal and silica gel beads.
Activated carbon, or active charcoal, has small low-volume pores that increase the surface area of adsorption. While it doesn’t bind with many molecules, due to its large surface area, it can still absorb a lot of particles. It’s cheap and relatively efficient. Unfortunately though, its effectiveness can decrease over time. So you will have to buy another set of charcoal adsorbent bags in case the smell persists.
Silica gel is a porous form of silicon dioxide. It has a strong affinity for water molecules, thus often used as a desiccant (substance that sustains the state of dryness). It is also often used as an adsorbent of musty smells including those of decomposed rat corpses.
An air ionizing technology is used in air purifiers to eliminate particles from air. Some purifiers also have charcoal filters for adsorbing unpleasant odors, which makes them a win-win option for a purchase.
Pro Measures: Acetic Acid, Chlorine and Formalin
Acetic acid, chlorine, and formalin are considered to be professional disinfectants. These chemicals destroy or inactivate most pathogenic microorganisms and viruses.
If you decide to use any of the fluids containing such substances, please, make sure you do so while carefully following the instructions outlined by the manufacturer.
These substances are considered to be the most effective in combating dead rat smell, or any other unpleasant odor. My old time buddy from high school, who became a forensic pathologist, confirmed that he was using formalin, acetic acid and chlorine to eliminate smells of rotting flesh. However, these substances are extremely toxic and can result in serious injuries. I do not recommend using any of these substances without direct supervision of a professional.
Which type is the most effective?
All of the above mentioned types are effective at eliminating all odors.
However, some might cover smaller area or become ineffective after a certain period of usage time. Others might work only after you discover a dead rat’s body. Professional disinfectants, although being very powerful, are dangerous for use in households and should be handled with greatest caution.
If you are not tight on your budget, I’d recommend spending an extra buck on an air purifier: look for the one that is efficient at eliminating odors using charcoal filters or any other similar technology.
TOP 5 best dead rat smell eliminators
Earth Care Odor Adsorbent
Earth Care Adsorbent consists of a blend of minerals, which makes it all natural, eco-friendly option.
The more packs you buy, the less you pay. One bag supposedly covers an area of 100 sq ft. The manufacturer also claims the odors go away after just 24 hours of use. The label states the bag lasts for 3 months, and then needs to be changed.
Bamboo Charcoal Deodorizer Bag
Each bag clears the air in a small space of up to 70 sq ft. You will obviously need to buy a lot more bags if you need to cover larger area or if the odor is severe.
The manufacturer promises improvements in air quality (odor removal) after 1 to 2 days of continuous use. You can reuse the bags over and over again after leaving them under the sun for 2 hour “re-charge” once a month.
GermGuardian 3-in-1 Air Purifier
This is an option I chose for myself when dealing with an unpleasant dead rat smell.
In case you or anyone in your household has allergies, then this product might be your safest bet: HEPA filter captures up to 99% of dust and microscopic allergens.
GermGuardian has charcoal filters that help reduce the common (pet foodstuff, smoke, cooking) and uncommon odors (dead rodents).
The air purifier also guards against and fights germs with the UV-C light technology and Titanium Dioxide.
Covers an area up to 167 sq. ft. Only one single filter needs to be replaced every 6-8 months depending on the use of the product.
All of the abovementioned benefits come at a high price of almost 80 dollars. But if all other options have failed, try GermGuardian.
Green Gobbler Ultimate Vinegar – 30%
Green Gobbler vinegar is derived from domestically grown corn. You can use it at full strength or dilute it with up to 5 parts water to create a gentle all purpose cleaner. It is 6 times more concentrated than regular vinegar, so be extremely cautious while using it.
Rocco & Roxie Stain & Odor Eliminator Spray
As a biologist I know that the products that remove the smell of urine, or any other organic smells, are effective against the dead rat smell as well.
This spray is an efficient eliminator of not only odors, but stains, stinky residue, and organic spills.
Rocco & Roxie spray consists of natural enzymatic bacteria that are activated on contact with odors and stains, feeding on ammonia crystals and organic matter. It’s chlorine free and completely safe around kids and pets.
While it won’t really work until you find the dead rat, but as soon as you do, the spray is potently effective at eliminating everything that comes in contact with it.
Comparative chart of Dead Rat Smell Elimination Products
Can a dead rat odor make you sick? // Is a dead rat smell toxic?
Smell is unpleasant, but it won’t cause any harm unless you are in an enclosed space with a rat without relevant access to oxygen (which will not happen unless you are tortured). Rotting flesh emits a bunch of gases, such as hydrogen sulphide, methane, and ammonia, which can become toxic in large volumes (and this is not going to happen either unless you are stuck in a room full of dead rats). A decaying body, though, can be full of harmful bacteria, which puts you at risk of catching infection.
Can a dead rat smell like rotten eggs?
The smell of rotten eggs is commonly associated with a natural gas or sewer gas leak. If there is a very strong smell, call 911 immediately.
Hydrogen sulfide and methane both are responsible for the foul rotting smell and can be released by the decaying body. So if you notice somewhat slight smell of rotten eggs, then yes, there is a possibility that you might have a dead rat problem.
How long does a dead rat smell? // When will a dead rat smell go away?
The rotting process depends on many factors, including exposure to water, oxygen, insects, etc. So if a rat is stuck inside a wall without much exposure to water and changes in temperature, the rotting can take longer, sometimes even a couple of months. The odor usually subsides when the carcass dries out, a little bit earlier before the decomposition is completed. If you don’t find that unfortunate rat inside the walls of your house, the odor may persist for a month.
How to find a dead rat smell?
Look for dead rat bodies in the attic, basement, and wherever else you placed your rat traps. However, if you used poison, dead rats can be literally everywhere, so it might be very difficult to locate where the smell comes from. If you suspect it might be coming from a wall, call a professional exterminator for help; from a sewage – call a plumber.
Before you buy any odor abatement products, try to find the dead rat’s body, and if found, discard it as soon as possible.
Always take prevention steps to minimize the chances of clutter and unnecessary objects for the mice and rats to hide and nest.
Try to avoid the use of chemicals (aka rat poison): when rodenticides are used the rats die painful death wandering through the premises before eventually dying, making it harder to identify the dead rat’s body.
Try using natural odor eliminators first before resorting to chemical alternatives. Otherwise, try an air ionizer if you can afford it. It will serve longer and can be used for other purposes.