Dead Mouse In Wall Smell How Long Until Dead Mouse Smell Goes Away?

How long until dead mouse smell goes away? - dead mouse in wall smell

I have tried to set traps and do not work, so everyone told me to put some rat poison. Well, that's swallowed it all, but now languishing behind the walls of my house and smells terrible. I do not think I can live long like this! How long until he starts to feel better?