Funny as it may seem I learned about rodents while serving in the military. Having to be in many different environments you learn how to combat these little jokers. In the desert, I used peanut butter. But lets get to this issue:
1. You need to have it identified what kind of mice you have as there are three types
a. Deer mice
b. Field mice
c. House mice (breed year round)
2. Once you have identified which mouse type it is then we can hone in on how to eradicate the little pest!
3. Now some people use poison and I am against it because those little jokers get into a space die and then start stinking. If they have been identified as deer or field mice then they more than likely are carrying fleas and mites, so when the host dies, these creatures then look for other sources. Yep, you are now on the food chain of subjects.
4. I am a fan of live traps and mice love oatmeal. If you use traps that snap their little bodies then get some Slim Jims. They cannot resist those Slim Jims.
There are other things to do like finding out there habits and understanding that they will investigate daily there areas, so you want to move things as they do not venture all that far from their nests. Mice normally do not venture more than 30 feet from their nests, so if you see a lot of them, then they have quite a few locations.
Normally a female will have about 50 young a year. So, you for sure want to identify like I wrote before which kind of mice you have. Once you identify the kind of mice you have, I will try to send you specifics which may be of use. I am not a licensed exterminator, just been in the trenches with these little jokers here and in other lands.