The Ultimateb Solution

is Bay Leaves. I agree with Linda and this has worked for me for years.
These critters are called Indian Meal Moths and they often come from grains from natural food stores, where they develop in sacks or barrels of grains. They seem to occur more in the more nutritious products ( whole wheat products more often than refined things etc). I consulted the regional agricultural agent when I first had them, and after cleaning all the shelves with a very toxic product and throwing out EVERYTHING they were infesting, I have strewn bay leaves on every shelf where I keet grain products and even keep a few leaves in an open baggie on top of the flour in the canister.