The last ones I found en masse infested some black tea bags I had forgotten about at the back of an upper shelf.

Huh, I thought black tea was one of the few things they don't infest. I'm gonna have to check those boxes, too.

I keep almost all my food stuffs in closed jars and I try to check regularly, and yet they are *still there*

We keep a lot of stuff in jars that shut tightly, and they still get in there. I even had to throw out a few packets of almonds and other things that were still sealed. Maybe they gnaw tiny holes through the plastic?

Those traps sound like a good idea, I'll try that, too. I'm pretty sure I didn't get them all, and the population bounces back freakishly fast.