Yes I agree. You might have saved those poor little snakes lives! If you had had not called attention to the mites the snakes could have been sold to someone with no basic reptile knowledge or no money for vet care.
You certainly did the right thing! 
Very true, im glad i did what i did, and i hope this post helps some newer keepers see why they cant just trust pet stores to have healthy animals. You have to research and do your own health inspection 
Amen to that! I think you have already educated some people!
My guess is that they will place another animal in the same enclosure without doing anything more than replacing the substrate. No way are they going to treat every enclosure and every reptile in them.
Kudos to you @verinium for bringing the parasites to their attention.
I HATE REPTILE MITES. I had them way too many times years ago. But you cant always see them on larger animals. Someone may have treated their stuff just enought to keep them at bay so they can sell them and you could still end up with them.
Be forewarned, its not just the Big Chain stores or even small Mom & Pop shops that have these issues. As hard as you inspect animals before purchase, mites can still find their way into.your collection. Too many times i had brought home these little pests from Reptile Shows as well. I used to sell animals at Reptile Shows as well but never sold animals that were infested. I got to the point that i used to spray my table before i set up and treat all of my sales furnishing the night before a show to prevent cross-contamination from other vendors animals. Even sprayed the cardboard boxes that i transported animals in with hopes that i wouldnt bring anything back home with me.
At least in the picture above, the Water bowl is a solid item, so it and the plants could be soaked in a bleach bath and/or prevent-a-mite to kill any mites. The log hide is a different story. Most of these types of cage decor today are resin material that have small holes in the bottom for manufacturing. The mites could hide inside and not be killed by simple soaking or spraying and just reinfest the next animals that get brought in. There are other methods they can use to clear the mites from the enclosure as well. Mites travel so they should really clean the entire reptile rack. They could also treat the bedding prior to use. I have methods for that too that work excellent but you have to be careful of other inhabitants. Arachnids, scorpions or other insect could be severly affected by the treatments.
I’m old school, we used to use a small piece of No-Pest strip outside the cages to help kill traveling mites and ticks. We also used to use small piece of NP strip inside a white athletic/tube sock inside the cage. We would leave this inside the cage for a couple days as a viable solution but even that is questionable today. Plus, you had to make sure you remove the water bowl before hand. The active ingrediant in NP strips is supposed to be denser than air and settle along the bottim of the enclosure and can supposedly collect in water. There are claims that NP strips can cause neurological effects if used long term. Recently they changed the active ingrediant in NP strips. The wording on the label makes me question using this anymore inside enclosures. It says not to use inside a closed room thats occupied for more than 4 hours. We also used to used Ivermectin for larger snakes as an injection but this was typically only available by vet perscription but i think ypu can get it from the Farm & Fleet stores now. The mites could still bite the snake but they would die from the medecine in the snakes bloodstream. Also works as a dip bath or a spray for the enclosure and furnishings.
An important caveat here. Yes, now adays Ivermectin can be bought OTC. However, it is EXTREMELY important to note the OTC dosage is meant for cattle, not small animals weigh less than 20kg. It must be heavily diluted in order to safely use with reptiles and you should only attempt it after much research, or the guidance of an exotic vet. DO NOT just grab Ivermectin from a store and use it pure on the animal, you will have a dead snake. If it does somehow survive it will have significant neurological damage to it, as Ivermectin is poison, not medicine. Its purpose is to does the animal low enough it doesnt harm the animal, but high enough that it poisons anything drinking the blood.
Do research before any treatment!
As for the rest of the post he is 100% correct, these guys are super small and under the scales of an adult snake, you may never notice them if they are receiving treatment. This is why even after a good visual inspection, proper quarantine procedures are important before mixing in with your collection. This example was a petco, but nowhere is exempt. The point was to always check potential purchases, not to bash retail.
Visual checks dont give 100% confidence of no issues, but it does catch some problems before they happen.
@verinium precisely why i didnt giva any dosage suggestions. I hope the people in this blog realize they should be asking questions before attempting anything themselves. The dosages for reptiles are typically give based on a 1% solution of Ivemectin as a base starting point. If anyone doesnt know what 1% solution means, they should be doing some research or asking a qualified vetranarian for help with that. But, using Ivomectin to treat an animal directly (subcontaneously) is a completely different approach from using it to eradicate mites from enclosures. And they should be protecting themselves with rubber gloves and possibly a good resperator of some sort if the are spraying it in reptile enclosure. Ivomectin is used to treat a lot of different things and even safe for use in humans for different things at different dosages and in different forms (tablet versus liquid). The internet is a powerful tool for doing research, but please make sure you are getting non-conflicting information from several sources before attempting anything yourselves. We didnt have that many veteranarians when i started keeping reptiles that specialized in reptiles. I was fortunate enough years ago to have one that understood my background and capabilities and that was willing to work me and help me understand the proper ways to administer some treatments to my animals. I doubt there are very many veteranarians today that would do this for any of us. But, this was well within my capabilities and also gave me the confidence to make further advances in my reptile husbandry as well as excell at my abilities to recognize and treat freshwater and saltwater fish diseases at the private pet stores I worked for over the years.
All medicine is poison. Sometimes it doesn’t affect the host at all. Sometimes they just accept the lesser of two evils.
I mean, anything is poison if you consume enough it haha. I should say that particular one is a nerotoxin rather than a medicine. Its intended purpose is to kill the bugs slightly more than it kills your animal. The risk is different, like ODing on meth vs ODing on tylenol. The risk is higher and its easier to do, but you are right most medicine is a poison if you have too much if it.