Animals such as squirrels, birds, mice, and rats can enter your HVAC system or ductwork and decide it's an ideal and comfortable spot to build a nest. When the animal dies, its decomposing body can produce a putrid odor that spreads through your home whenever the heating and cooling system is one.
One of the worst things that can happen to your HVAC ducts is having a dead rodent get trapped inside. As its body starts decomposing, it will emit a rank odor that permeates the entire house.
If you choose to wait it out, it can take up to 3 weeks to a month for the stinking odour to pass. After this time, the carcass has had enough time to completely dry out, and the rotting process has passed through its most noticeable phase. A decomposing mouse smells like propane gas or rotting meat.
Signs of a dead animal in your air ducts
Unusual Odors: Noticing a strong, rotten smell coming from your vents that seems to get worse overtime? It could be a sign of a deceased animal.
If your furnace smells like a dead animal, it's possible that it IS a dead animal (like a squirrel, mouse or rat). Unfortunately, something may have crawled into the furnace and gotten trapped. This can happen if there are gaps in the furnace that provide access to the interior of the cabinet.
Carbon monoxide gas is colourless and does not smell, so you cannot tell if it is around you. Symptoms of carbon monoxide poisoning include: headache. dizziness.
Just open up the closest barrier or vent cover, reach your gloved hand in, grab the carcass, and then place it in your bag. The gloves that you wear should be disposable. You will need to put these in the bag too, along with the dead animal. Seal everything up and then put it in the dumpster or waste bin outside.
The smells coming from a dead animal are unpleasant, and they can often make you feel like you are going to be sick. However, simply smelling a dead animal is not likely to affect your health.
You'll have to turn off your HVAC system and remove all the vent covers. You'll need to load a trap for each vent. Most do-it-yourself-ers use snap traps baited with peanut butter, meat, or cheese. Place the trap just inside the vent and wait.
Mould and mildew love moisture, so when there's excess moisture in the ducts and vents in your air conditioning system, it's creating the perfect environment for mould to grow. When air is blown through the vents or ducts, the musty smell will spread through your home.
A putrid sweet odor so strong it can make you gag or even vomit if you get close enough to the carcass. The warmer the weather the worse it gets. Once you realize what the stink is you never forget it.
A dead mouse should not be left to rot inside your wall, because its corpse could soon attract fleas. With an electronic borescope, you can locate the corpse's whereabouts by drilling a coin-sized hole, a few inches off the ground, into the drywall of the cavity that seems to be emitting the smell.
Dead animals will smell until they are entirely decomposed or dried out. The damper the site, the longer the odor will last. For example, if a rat dies near a steam pipe, the smell can be horrible for weeks, but the odor from a dead mouse may last only a day.
Rodents like rats can easily access these ducts, bringing with them noise and health concerns. Duct-loving animals tend to chew through insulation and electrical wiring, too. And it's not just rats. Pros have found squirrels, birds, bees, and all kinds of creatures up there.
Turn off the Vent and Clean It
Thoroughly scrape the urine stains off the surfaces. After the system dries completely, spray hydrogen peroxide to disinfect the remaining microbes and kill the bacteria. Vinegar can help neutralize and mask the ammonia-like urine odor, and stop the pet from urinating again.
Whether it's extreme heat and cold or searching for food, animals can accidentally end up becoming trapped inside your HVAC System. The result can be a very scary experience for you and especially for the animal.
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.
If there's no evidence to point you in the direction of an impromptu mouse graveyard, follow your nose to the most concentrated area of the stench. If there's still no sign of the corpse, it could possibly be in an air duct, a wall cavity, the attic, the crawlspace or in the sealed underside of a kitchen counter.
Aside from the smell, there is also the risk that the animal may have been carrying harmful microorganisms that could blend with the air that is released through the vents. If this situation is not remedied right away, your indoor air quality is reduced, risking the health and well-being of your family.
One of several culprits could be mold in your drip pan.
If the part of the drip pan where the condensation runs is not draining correctly, then unblocking the clog will help; or if the condensate drain line is the problem, then replacing the line should eliminate further problems as well as the smell.
To remove the animal, you can also easily set traps around your home. You can set live traps near the vents in order to let the animal leave the ductwork and be captured humanely and removed alive from your home.
Charcoal briquettes are a surprising yet effective method to remove the dead animal smell. Try placing several briquettes in a bowl and place them where the smell is the strongest. You may need to do this for several days to eliminate the smell thoroughly.