At what point do you get rid of scraps?

I’m currently dealing with a moth infestation (☹️) and am cycling everything I have into the oven to bake whatever might be on there. As I’m going through my stash, it’s making me really take a look at what I have saved and think about whether or not I’m going to use it. I have a lot of scraps and partially used mini skeins, and I thought I’d ask my fellow knitters how you decide whether or not to save scrap yarn. Do you keep the colors you’re really attached to? Do you get rid of little balls once they fall below a certain weight? Is it just vibes?