I have used a good many mothballs for a lot of things over the course of a number of years, and have yet to have a problem. They keep deer out of places where they don't need to be, and have worked pretty well in the garden when the deer decided to eat my strawberries and sweet corn. I've also used them when I had a dog that wanted to dig holes under the shrubbery next to the house. A couple of mothballs in the hole would keep her away. I've never had an animal attempt to eat one, at least that I'm aware of.
