I'd venture a guess and say a wood mite. Which could have hitched a ride in a wood based substrate or piece of wood furniture that was stored near other wood materials. Wood mites feed on decaying wood and pose no danger to a snake. That being said, theyr'e still a nuisance. But without any definite description its hard to make an educated guess.
The water bowl is a frequent place to find them. They get thirsty and fall in, and the slick sides of the bowl prevent their crawling back out. Wood mites and snake mites do this. Also if they're snake mites, the snake will soak in the water to try to drown them off. So I'd look throroughly all over the snake paying extra attention around the eyecap and in the main cleft under the chin where skin is exposed.
Reptile Relief is a God-send. I bought a snake about 3 years ago infested with snake mites, only found it out after I get the snake home. 3 treatments of spraying the snake down with Reptile Relief and letting him sit for 30 mins in a bare container and then wiping him down to remove any Klingons.
You can also use it to clean your viv for mites/ticks/bugs. Just clean the viv's litter out and remove everything and spray it down all around the lip of the cage (I assume you're using an aquarium), down the corners to get around the silicone seals, and let it sit for 15-30 mins and then rinse it out with a hose and dry as normally.
Its pesticide free and works by basically drowning the bugs. It coats their external openings for their breathing and suffocates them without harming your snake. You can spray it directly on the snake, or apply with a rag.