Annarose15 you beat me to it!
yeh, i was gonna say, FIRST thing i would do is grab that snake and look him thru, stare in between some scales for a while, gently grab his head and stare at his eyeballs, mites are my biggest fear ever nowadays. Then after thats done, i would ask about eveything else.
And of course, spray down the enclosure you intend putting him/her with PAM before you bring him in, and lines with papertowels so if he does have mites u can see them when they die off.
Im so paranoid of mites, every week i take my BP out and inspect him, i grab his head by his cheeks (thats what i call the meaty part on the side of his head) and inspect him thoroughly, its gotten to the point that once i grab his head there, he knows the deal, he dosent even bother to fight me he just stand still and lets me look him thru