Itâs not uncommon for uninvited rats and mice to invade your home especially when it gets cold. And some of them will die and cause a stink! A dead mouse will emit a pungent smell for 6-10 weeks until it's fully decomposed. Larger rodents like rats will smell worse and take even longer to decay thus causing a bigger problem. In addition, they can also make you sick because of the multitude of diseases they carry. Learn How to Get Rid of Dead Mouse, Rat and other Rodent Smell from this video and keep your entire home smelling clean and fresh without spending a fortune. A smell free home is also a sign of a healthy home. So get the harmful dead animal smell out because clean air a matter of your health and we do wish you well.