I had something similar, but I wouldn't be able to tell you since I just got rid of the soil(it wasn't much). I searched "soil mite" try that and see if it matches yours. Hope this can lead you or get you close to identifying.
to me they look like ants but could also be termites.. is there bark or wood products in your soil? so my first guess is ants.. its really had to tell without a better picture..
Springtails. Send 'em to me and I'll use them to feed my tailless whip scorpion babies. Termites don't like being exposed to air/sun. You'll rarely, if ever, see them wandering around up top.