It depends on the type and size of the animal as well as temperature and humidity. Typically it takes 3 days before an odor is noticeable.
It can take anywhere from a few hours to a few days before you start to smell a dead animal, depending on various factors such as the size of the animal, the environmental conditions, and the presence of scavengers.
YES.
there could be a dead animal in your vent
...Cycle of life
A gas smell has a rotten egg odor due to a chemical gas companies use to make gas leaks easily detectable. A dead animal smell is caused by bacteria and fungus as that form as the body decays.
Most likely they smelled like whatever they walked into.
A dead animal smell coming from your furnace could be due to a small animal getting trapped or stuck in the ductwork or near the furnace. It is important to have a professional inspect and clean the furnace to remove any remains and eliminate the odor.
Actually it doesn't take very long for a hermit crab to smell when it's dead. They will not smell if they just died. About 10-15 mins they will start to smell. You have to put the hermit crab up to your nose in order to smell the rotten fish smell.
Its because od decomposition of the body ......
There could be a dead person or dead animal in the house, or spoiling meat as from a refrigerator or freezer. Vultures are attracted by the smell of carrion and many species have an exceptional sense of smell.
A dead mouse can start to smell within a day or two of its death. The smell can linger for about a week or more, depending on the conditions such as temperature and ventilation. Proper removal and cleaning are essential to get rid of the smell effectively.
The smell of feces is due to molecules produced during the breakdown of waste material by bacteria in the gut. This process generates compounds like ammonia, indole, and skatole that can create a strong, unpleasant odor. The similarity to the smell of a dead animal may be because both involve decomposition and the release of similar volatile compounds.