I had springtails once that I knew of and may have had them prior to the time I saw them. It would be easy to miss them. I only noticed them in the run off water. I could see them with the naked eye once I knew what I was looking for and could see them bouncing around in the runoff water I collected. I never took a close enough look to see them on the surface of the soil. I read most are harmless even beneficial to the soil. They feed on fungi, algae, and decaying organic matter and when they die they add nitrogen to the soil. The time I had them I did not notice any affect on my plants.