After a rat dies, it usually takes about 3 days for the smell to begin, and it stops smelling after 14 days. But it's not that simple: many factors can influence the odor, such as the location of the carcass, the size of the body, the temperature and humidty, and the ability of flies to access the carcass and maggots to start eating it.

I recommend that you remove the dead rat, bag it, and throw it out. But sometimes the dead rat is stuck in a wall or attic, and it's hard to find. But you're in luck! As a potential health risk, many free agencies will help you remove the dead rat in your house! Click on these hundreds of US locations for free animal help, and you will find several government agencies in your town that provide free services, such as the city or county animal services, the state wildlife commission, the local USDA branch, and more. You need an expert to find the source of the odor, and cut a hole in the wall or ceiling to remove the dead rat, and stop the smell and the health risk.





Animals like raccoons, opossums, mice, squirrels and rats can find their way into basements, attics, air vents or even plumbing; and while some of them find their own way out, they sometimes get stuck and have to be pulled or coaxed out. If you’re lucky, you’ll discover the little rodents while they’re still alive and call someone to come and get rid of it, kill it or, preferably, release it back into the wild. But not everyone is always lucky and some people only discover they had a small invasion when the dead animal starts to smell.

So, what happens when a rat dies in your house? It will start smelling, very badly. It takes about three days for a dead rat to start smelling. This also depends on the temperature, as a cold environment will probably prevent the dead animal from starting to smell as quickly. The odor will be very subtle at first, maybe a smell that comes and goes, or an occasional whiff of something rotten. But by the third day the smell will become overpowering, it is after all a decomposing animal.

The strength of the smell will depend on the location, temperature, humidity and state of decomposition. If the dead rat is in an air vent, you can be sure that your whole house will be permeated by the stench, if it’s located in the attic or near a window or outlet the odor may come and go. The temperature is also a big factor, as a dead body will decompose more quickly in higher temperatures. If you live in a very humid area, this will also mean that your sense of smell is heightened and moisture will accelerate decomposition.

The smell will gradually subside, as the dead rat’s carcass decomposes and disintegrates, the smell will fade, but this may take weeks, especially if it’s in a hot and humid area. Hopefully you will not wait that long before calling the professionals to remove the dead rat, as the foul odor of a rotting dead animal can permeate your house and it’s very had to get rid of. It sticks to your furniture, your curtains, to the walls and even your clothes and is incredibly hard to get rid of. That may call for another team of cleaners, specialized in deodorizing and sanitizing the affected area, or if need be, your whole house.

If you find a dead rat in your house, it’s because only days earlier you had a live one. That means you must find out how it got there in the first place and take the necessary precautions to avoid it happening again.

Read the How to get rid of rats page for helpful information about rat control and to learn more about how long does it take for a dead rat to start smelling, and then stop smelling.