Typically a dead rodent mouse rat squirrel or other will emit a foul odor for a week to a couple weeks.
Dead mouse in ceiling.
Dead mice can be deposited into a plastic bag to take out with the trash or directly into the outdoor garbage can.
If a dead mouse carcass is inside a wall or drop ceiling or any other inaccessible cavity the best method is to move back and forth with your nose against the wall or ceiling sniffing and sniffing.
But below are some tips so you can avoid that.
Set snap traps along the mouse trails.
Along ceiling joists set two traps side by side with baits at opposite ends.
The good news is that you won t have to live with the smell of decomposition forever and you don t have to tear apart your wall or floors or ceiling or put the house up for sale.
If you re too squeamish to undo a snap trap to release the dead mouse you can.