It does pretty good keeping a certain kind of moth out of the flour. I live in the county and I get what is called a confused Indian meal moth. Although i have seen it written that it doesn't work, [bay leaf] it seems to work for me. I don't know if people who live in town have this problem. Or if it works on another kind of insect that likes to get in flour etc. But I have never been bothered with anything except the moth. I try to keep most things they like to get in to in glass jars. Plastic bags don't work. I have seen where they have eaten a hole in the bag. And any jar other than a canning jar doesn't seem to work either. I am glad to see others that use the bay leaf so it can't be an idea that doesn't work.