Dead Mice in Walls
Some rhodent baits advertise that the dying mouse or rat will go outside to die after eating this bait. I suggest you get one of these poisons so that any remaining (or new) mice will go away to die.
Hope that helps.
Poisons, while much handier to use, can cause this problem. Instead, I bought a dozen of those plastic, spring-loaded mouse traps and mounted a daily offense against the mice. It worked and no odor from dead mice crawling up inside walls.
Mice can enter teh tiniest of openings. you need to crawl around under your house looking for openings into the crawlspace and into the interior of the house. Common entry points would be where pipes and electrical conduits routed in the crawlspace go up into the house. Often there is a gap. Fill those gaps with steel wool.