When we moved here from the city our shed had a family of skunks living under it. I heard about the moth balls, so I go buy them, throw them under the shed,wake up the next morning,all the moth balls are pushed out from under the shed and are laying around it. I guess my country skunks where smarter than this city girl, I still laugh thinking about them pushing all those moth balls out from under that shed. they finally moved on and we tore that shed down, and built a new one, I, by myself added a 12 inch rat wall around the base not to have that problem again.