Question

Question
I bought a king california snake I would likley want to know what cause mites can it come from the bark im using zilla bark and if so whats the best advice I can get to avoid those creatures

Answer
I think you mean California King Snake.  Mites are small arachnids (related to spiders) that crawl onto snakes and then suck their blood.  There are millions of different species of mites.  There are so many that there are mites which infect other mites!  You have mites in your eyebrows right now.  Prevention...  don't take your snake outside, use frozen mice, sterilize the tank and the surrounding area, and perhaps prayer...

Easy way to get them off the snake, place him in a small plastic container with a lid and pout olive oil all down his body, leave him in that for about 10 minutes.  While doing that, THROUGHLY sterilize the tank and cage furniture with a 10% bleach solution, throw out the bark.  Restart the tank, rinse the snake with warm slightly soapy water.

I am not familiar with "zilla bark" so I can't comment.  I use shredded aspen which is cheap and economical.  It is possible either the bark or some other piece of cage furniture was infected in the pet store you bought it from.