I used to own a feed store and sold a product called "fox urine." And yes it is exactly that! Tell your friend to go to a local feed store or a lawn center that specializes in organic products. Take a couple of those little 35mm film canisters & put a few small holes in them. Put a few cotton balls in them & pour a little of the fox urine in it and throw it in the crawl space or attic. Wala-they're gone! IT works on all kinds of little critters. Racoons, skunks, squirrels, etc. Anything that would be a natural enemy. One word of advice though! Do not get it one yourself!!!!!!!!!!!!!!!! Nasty! Wear plastic gloves. Hope that helps him! Let me know!