I've been suspicious of mites as well, but I absolutely cannot find any signs of them. I've checked him over more times than I can count, never found mites in his water dish (he doesn't try to soak though) I've given him a few baths in the past 4 months that I've had him, never a speck of anything in his bath water. The vet looked at him under a magnifying glass for quite some time, but also could not find a single mite. Do you feel I should treat for mites anyway?
The vet probed him to determine the gender of my snake.
Edit: Also should probably add that my snake has been living in captivity at least since he was a baby (5-6 years old) though his previous owner was not taking very good care of him. My vet told me she did not feel his chin's red spot was tick related, but I am taking her word with a grain of salt at this point.