Some friends of mine reported one evening at music that they had a 'pet' mouse that was really cute, and they were laying down bits of cracker for him. We assured them that if they see one mouse frequently, there are a lot of others in the cabin, but they weren't so sure.

A week or two later my friends said they had to put their foodstuffs in metal cans because they had discovered that their 'pet' had got into everything.

A week or two later, my friends said they had purchased a live trap and were catching a LOT of mice in it; every morning they took one or two mice out into the woods back of the cabin and released them.

A week or two later, my friends said they had set old-fashioned snap traps around inside the cabin. They said that it seemed like the released mice beat them back inside. :)

In times past I used to leave pantry and cabinet doors open over night every night. As some said above, I think just the presence of a cat that has access to them tends to send mice down the road.