Asked in Care of Mice and Rats
What to do if you come across baby mice in your boxes?
May 13, 2012 12:28AM
That depends on how you feel about it being there, and how old it is!
Likely, if there are multiple mice, it is because momma thought your box made a nice safe nest and decided to raise her family there. This is especially true if the baby mice are hairless (ie, under five days old) because pups that young are not mobile.
If you don't care about mice in your home, I suggest simply leaving them there. If you don't want mice in your home but don't want to kill them, you could place a humane trap by the box to catch momma and release them all at least a mile from your house. Mother mice need to return to the nest to feed their offspring at least every two hours or the babies will die. Momma probably wasn't far.
If you do not wish to have mice in your house at all, the (arguably) most humane way to kill the pups is freezing them. There are other methods used by mouse breeders, but they require special equipment or knowledge. Again, remember to trap momma and kill/release her. If you simply trap momma and leave the pups, they will slowly starve to death, and that's not a fun way to go for any creature.
If the pups are furry with bright open eyes and moving around, you've got hoppers on your hands, and they can survive on solid food. They will need to be dealt with in a similar way to an adult mouse.