I freeze mine for a week, too. I'm a birdkeeper mostly and several years ago I got an infestation of moths that I STILL can't totally get rid of, though it's way better now. I transitioned the birds off seed and onto pellets, and the hamster mix goes straight into the freezer when I get it.
What about lab blocks? I wonder if I should be freezing those too.
If it helps, I live somewhere you can NOT leave flour/cornmeal/rice/spices out without it getting full of weevils or beetles. I have had the terrible experience of cooking dinner and not noticing until I went to take a bite that the spices I used were full of beetles
