If it looked like these then it very well could have been some kind of a mite.
If I have reason to think that my snakes might have mites, I give them a soak in water for about thirty minutes (sometimes longer) which will either drown some of the mites or make them crowd to the snake's head or back where they can escape the water. Cleaning out the tank and pouring boiling water over it will also help kill any possible mites that may be there if you don't want to spring for Provent-A-Mite (abbreviated PAM) just yet. Then just keep an eye on your critter for the next week or so and swap your substrate to paper towel. If the mites are wood mites, they'll pretty much die off with regular cleaning and a lack of substrate, or PAM if you decide to pick some up. If they're snake mites then you'll probably see most of the mites cluster around the cloaca and eyes, you may also see some in between the scales or dead in the water dish but personally I've only seen this in really bad infestations.