Help! Little white bugs?

[monstresque]

My poor Calcifer's terrarium has tiny, almost invisible white bugs crawling around on his hides and in his substrate, though I can't actually see any on Calcifer. My first thought was mites, but then I read something about springtails, and now I just have no idea. I have no experience with this kind of thing. What are they? What caused it? I never noticed them before now and I'd thought I'd been keeping a pretty clean tank. What do I do?

[Dakota]

Wood mites? They're harmless to the skink.

[monstresque]

I honestly can't tell. They're so small. And of course I googled them and the top results were the worst possible scenarios.
I cleaned out the terrarium just in case, and am hoping it's just wood mites.

[Edit: I got worried right away because I follow a few reptile blogs who have some horror stories about mites/ticks/etc... I just don't want to downplay it only to have it turn out to be much worse than I thought.]

[Susann]

From what I understand, I have no experience what so ever, if the critters that are moving around are white, they are wood mites --most likely came in with your substrate-- and are harmless to your skink. The reptile mites you need to stay away from are always black, or a very dark color.

[splashy07]

I've got 'em by the hundreds in my community tank, and they actually pick up after the lizards! Freaked out at first too, till a friend told me what they were. Black crawling dots are the bad ones, and when you squish them blood comes out.
Mine must have come from the substrate too, and never seen one on a lizard.