[Amethyst_ice]

Hello,

I wonder if you may have book lice? In my old house, it was quite dark and damp and I found really tiny little bugs on lots of surfaces. I took many photos and book lice were the closest identification I could find, they were tinier than a pinhead.
I never fully got rid of them but they survived better in damp climates so after my initial big freak out clean, I only found the odd ones here and there and kept the house as well ventilated as I could.

As you have been freezing everything and had new bags open etc, it sounds more environmental. We have had some very hot weather over summer and having windows open etc, all sorts can get in.

It's unlikely they would "bite" Percy to make him itchy, hamsters do itch like all animals, is it possible you are on high alert and it seems like he is itchier and thus worrying you?

Hope you get it sorted, all the best