Bugs are already in the flour when you buy it actually. Tiny and not seen😬

I don’t know about oats and rice but I put flour in freezer for a couple of days before it goes into cupboards.
Kills pantry pests (little black bugs).

If you are successful with “bastard mites”, I’d longs to know what method you used. We have them in both cupboards AND wardrobes 🙄

Could I bother you for one please if you have some spare?

Yes, I have two, only one does that. He gets so much comfort doing it! We also have scratched shoulders and clothes full of holes!!
Sorry for the cat spam, I never miss an opportunity to show off these two lovely boys 🤣