I’m glad one of the comments mentions that even leaving them in there overnight can cause a mouse to die. Stress, or if they’re already not fairing well (and why they resorted to seeking a new home) can cause them to die quickly if they are trapped in one of those live traps.
The best solution is to fix how they are getting into the dwelling to begin with (“exclusion”).
I’m glad one of the comments mentions that even leaving them in there overnight can cause a mouse to die. Stress, or if they’re already not fairing well (and why they resorted to seeking a new home) can cause them to die quickly if they are trapped in one of those live traps.
The best solution is to fix how they are getting into the dwelling to begin with (“exclusion”).