The Truth about Mothballs
To prevent moths, I wish I could tip you off to some effective herbal or natural treatments, but I can't. Some folks swear by cedar oil, but even cedar-lined closets aren't usually sealed tightly enough to retain the oil. Besides, if clothing already contains larvae, the cedar won't kill them and you'll still wind up with moth holes.
DDVP (in strips) or PDB (mothballs and flakes) are the only sure-fire remedies against moths and carpet beetles, which both attack clothes, as well as other pests. They must be used in a sealed area, preferably in a perforated container hung high because fumes travel downward. Be sure to keep out of reach of children, as both are very toxic. Camphor is pretty effective, too, and some people like it because it reportedly doesn't build up in body tissues like the other products.
Don't use DDVP or PDB near plastic dry-cleaning bags, coat buttons or metallic fabrics. These chemicals can make plastic become sticky and may damage your clothes; they may also cause leather to fade (you don't need to protect leather from moths anyway).
Say no to carpet
And avoid laying carpet in storage closets. It's soft and warm—the moth equivalent of lover's lane. Always vacuum and dust closets and drawers thoroughly before putting clothing away.