What are these bugs crawling on my top soil

Soil mites eat gnat larvae and pest species of mites. I throw a little party when I see them in my planters.

A little dawn soap mixed in water and give the top soil a light spray. It will kill mites on contact. Repeat as eggs hatch.

High Happy91, personally I want my growing environment to be as clean and sterile as possible, because you smoke it and its supoosed to be healthy or medical. Of course... nature brings all kinds of things with it and I just don't think flies or vermin are sterile. I add my own bacteria and fungi to the soil, so the effect of flies and other insects is unnecessary because they live on your soil or plant. What you can try against flies are fly adhesive strips and when all the flies are dead try nematodes to kill all the larvae in the earth. nematodes are not bad for your plant but they feed on the larvae and then starve as compost. Good Luck!

DE was applied as a dry top layer above soil.

I have also used Diatomaceous Earth also.