A clearer picture would help, but I’ll chime in on the other end of the spectrum. Soil mites. Most soil mites are not harmful to plants and can even be beneficial. They are tiny creatures, usually less than 1/16 inch long, that live in the top layer of soil. They feed on organic matter, such as decomposing leaves and roots, and help to aerate the soil and break down organic materials. In fact, their presence can be an indicator of healthy soil.
You can watch a youtube video watching decomposers doing their job. They don’t want anything to do with a live plant. I found a soil mite in my media during veg stage, did the research and left it there. Chances are there was more than one. I actually started leaving necrotic leaves on the media for it.
In conclusion, do nothing. It’s important to distinguish between beneficial and potentially harmful mites. * Most soil mites are beneficial for your plants.