Them be mites, all right. You may not want to embark on a campaign against
them without the consent of the snake's owner, since really nailing them
seems to involve toxic substances.
The conventional approach involves a no-pest strip or m***equivalent.
Details vary. I've successfully used a 1"-square piece of strip, in a
snakeproof container with holes (this is important; you DO NOT want the
snake to have any chance of coming in direct contact with the strip); the
strip goes in the snake's enclosure for three days, then out for three
days, repeated three times. (This is the approach recommended by a
recent Vivarium article on ball pythons; the author says that he's done
it repeatedly and never lost a snake.)
I've heard that there are now mite-killers that are less hazardous to the
snake. I don't know anything about them, but I'd like to hear more.
Post Scriptum: If the snake isn't in its original enclosure, its usual
home will also need to be treated; mites lay their eggs in corners of the
tank and such places.