Don't use moth balls! They are poisonous to birds and not too good for people to be exposed to. They are used to protect clothing that is being stored from clothes moths, and I would bet what you have are flour or meal moths, so moth balls would be useless anyway... unless you want to put mothballs in your food!
We've had occasional infestations of the moths. We think they've come in in dog food. They can also come in in birdseed, though a lot of seed now is packaged specifically to not allow any moths or bugs to survive.
The moths are harmless but annoying. They will lay eggs in any sort of dry, grain based food - cereal, flour, pasta, rice, crackers, bird seed, dog food, ect. You can usually tell what food has been moth infested as you will see little stringy 'cobwebs' on the side of the container. The only solution I know of is to throw out food that they've gotten into (or freeze it for awhile to kill them) and keep foods in airtight containers so they don't get in.

Karen
Chico (conure) and Pippin (budgie)
WI

Yep like Karen said.....freezing is the only way I know of to get rid of them as well.