Mothballs have worked for us for 15 years. I fill 6 small plastic glasses with mothballs (usually 1 box will do) I place a glass in the cupboard under the sink in the bathroom, under the kitchen sink, under the bed storage area and behind the couchs. I also set a few around on the floor. Yes it smells like grandmas attic but the mice hate it. Before we begin our season I throw them away, open the windows and in a day the smell is gone. Only problem is being able to find old fashioned mothballs. Smaller hardware stores usually carry them.