If there's one thing I don't miss about living in the country, it's mice and flies. Okay, two things. But mice were probably the worst. We lived alongside a field that was often planted to corn, which is a crop that attracts raccoons, blackbirds and mice. Lots of mice.
In an older house, it's impossible to keep them all out, so it was a real battle in the fall of the year to keep things safe from them. I learned to use glass jars to store any grains, meals, flours and cereals. I used metal containers to put mix packages or boxes in. The pantry was booby trapped with mouse traps and the cats waited patiently for any that successfully ran that course.
Even with that, mice loved our warm, snug house more and more as the winds grew colder and the nights longer. I'd hate to think how many we would have had if we hadn't taken those steps to rid the house of them.
One thing I learned was that mice and other rodents always come back to where they were born, so never, ever let a mouse live that was born in your house. She will return to have her babies and her babies will grow up (in three months) and return to have their babies. You can't win in a situation like that.
Humane Mouse Removal
Eliminating Field Mice
Getting Rid of Mice