Metal bins work better than plastic if you can get them. Those little jerks chew right through thick plastic. Toss some baking soda in the bottom before you add new feed, helps keep it dry.
It's wild how we just accept some problems as normal until someone points them out. You get used to losing a little feed, or finding a few holes in a bag, and it becomes background noise. Makes you wonder what else we're putting up with because fixing it feels like too much work.