There's much worse smells than mothballs ! A couple of my friends (Pete and Glen) used to live on narrowboats (canal craft - up to 72 feet long, but with a beam under 7 so they can get through narrow locks). They'd spent an evening in the pub near their moorings and at closing time one of the catering staff gave Pete a big bag of fish heads for his siamese cat, Paget. As was their habit they took a bottle of scotch back with them and retired to Glen's boat to drink it. Paget attracted by the smell of the fish joined them on the boat, and quickly found it's source. Realising that he couldn't scoff the lot, Paget decided to hide the remainder in all the nooks and cranies of Glen's boat while Pete and Glen finished their bottle. It took Glen weeks to find the last of the fish, and by that time they smelt so bad that even Paget wouldn't go onto Glen's boat !