Dryer sheets

A mouse only needs an opening the size of a dime to get in. Good luck finding all of those! While camping at Squaw Leap many moons ago (yes, bad taste, and the name offends the Native Americans who live there), we were invited to check out their food storage areas and the traditional sleeping quarters. Both were lined with the local version of bay leaves to keep out the rodents and bugs. They said that it is very effective. Not such a bad smell either.