Death Valley

Do you have any traps or anything like that, that can kill or hurt your mice??

What I am going to suggest is some where small and in-closed. So they can hide and not be found. If you have cats and they don't eat mice like mine they probably will be playing with them and scaring the mice to death.

look in tight spaces.put some food out for them.eventually they will get hungry.turn off all of the lights and just sit quietly and listen.I sure hope you find it

i lost my hamster once

Look in dark corners, such as closets, drawers, or food cabinets. Leave out food for your mouse in these dark corners and the next day see if there is any mouse poop. Good luck!

Given some of the questions I have seen, I wasn't totally sure it was really a question (sorry for any mistakes).
Like others, the mice like small dark spaces. I would suggest you try to locate something call a "live trap" that will catch them but leave them unharmed. Bait it with their favorite treats, bedding, water.

Good luck. My sister children lost their hamster once and it showed up, still alive and well, about a month later.

Oh, and you may want to post this question under rodents, instead of birds.