Set a mouse trap to catch a mouse, he ate the poison that was in it but didn t get caught. How long will it take for the poison to kill him?

Hopefully it won't die in your wall and stink up the place...I always use peanut butter.

usually less than a day

Depends on the poison. The most effective ones do not make the mouse feel ill - so he will come back for more. What it does is thin its blood till it falls asleep and never wakes up.

depends on what the poison was, how strong it was, how much the mouse ingested and how strong the mouse was (or is).