I know what you mean about an exploding collection, I started with king snake, then got into the balls, now just picked up a 'dwarf' reticulated python that is going to grow to be over 10 feet!! I'm addicted HA!
FYI, I would probably keep them on white paper towels, spray down the paper towels with water and a spray bottle. Then ball up several paper towels and spray them too for extra humidity. Then cover most of the top so the humidity doesn't escape. Then buy some 'Natural Chemistry Reptile Relief' spray and wet a paper towel and wipe down your snakes. Mites are almost impossible to see, they burrow in between the scales of the snake and look like black dots, nearly impossible to tell it's a mite unless you have an all white snake that has black spots. Once wiped down they will all crawl out and crawl all over the paper towels and you'll see them clearly. I battled mites for a month once I found out I was infested. Just picked up a new snake, wiped him down and one lone mite came crawling out! They reproduce like crazy so you have to catch them early to prevent an all out outbreak.