I had a new snake come in that brought mites into my collection. I thouroughly cleaned everything in the rack and individual cages-tubs, hides and water bowls soaked in boiling water. Soaked all snakes for a while to remove some of the mites on them and reduce irritation. Sprayed Black Knight in the cages and around the rack area. I use paper substrate so that was no problem to replace and spray. Lightly sprayed the snakes that weren't in active shed cycle. No more mites. Repeated twice over the next couple weeks just in case. I saw no ill effects from the treatment on my snakes (I keep Brazilian Rainbow boas, a Carpet python, Asian Mandarin rat snakes ranging in age from yearling to adult, a Taiwan Beauty snake, African house snakes and a Mexican Black king snake just in case you are wondering what types of snakes I treated). Check out vpi.com "the war on mites" for some useful information on various mite treatments also.
Good Luck!
Lora