I had mites once on one of my snakes, ironically about a month after I got it. I did a thorough exam when she got here and saw nothing, QTed her for one month, and not long afterwards she had them. I'd say yours probably had them from wherever she came from. I sprayed every one of my snakes with reptile spray regardless of the fact that I saw no mites on any of them, thoroughly cleaned every snake tub with green soap, wiped down the entire rack and then sprayed a mist of PAM on the whole rack, and the surrounding carpet as well. I followed up every 2 weeks with a spray down on the snakes of Reptile Spray, for 6 weeks, just to make sure. It's better, IMO, to be proactive than to try to fight an outbreak later. Good luck!! Get some Reptile Spray for sure!