Those I believe if my entomology is correct are grain mites they are eating the food you put in your springtails so they will not harm the springtails. I believe the bad mites that harm the springtails are more cream colored. I had some mites in a springtail culture I let the food source run out for about a week or two and then started re feeding and the mites were gone. If your feeding mushrooms, fish flake, or grain products you have a better chance of getting grain mites. Someone correct me if I am wrong. I feed my springs mushrooms and have not seen mites as of yet. I have them on mite paper but many people feed active yeast and have no mite problems.