beneficial mites

Upon tending to my tent plants I noticed the top of my coco was moving and found what I searched to be hypoaspis miles. After hearing they're beneficial and have seen no damage to my plant, my question is how did they appear? I'm using coco coir super soil with down to earth vegan mix and neem...

Have had collemboans(ie springtails) and hypoasis miles mites in my rock wool ebb and flow tables for about 10 years... i never introduced them but have noticed they continue to thrive throughout the room and had been wondering if anyone else has these little guys in their substrate and what...