Experts and BHG readers answer.
Thanks for writing. Mice usually populate areas where they feel safe --- so look for areas that provide habitat (such as debris piles, areas with lots of mulch, particularly thick plantings, etc.). Change the areas so the mice don't feel as safe, and they should go elsewhere. You can also try trapping them if populations aren't too extreme.
Of course you should also take a look at your home and see if you can identify how they're getting in --- large cracks in the foundation, vents, etc.
---Justin, Senior Garden Editor, BHG.com