probably fungus gnats. I had em. Theyre hard to get rid of. It sounds like youre using soil. Im hydro. I used azamax and added it to the res for 24 hours, this kills the adults and larvae but not the eggs. So you have to apply again 5 days later to kill the hatched eggs/new larvae. I also sprayed with PureSpray Green. Also a cup of Apple Cider Vinegar with a couple drops of liquid dish soap attracts and drowns them. If you dont see any in the cup in a couple days, it means you either added too much soap or not enough. Also get yellow sticky traps. If you can, cover your soil with something So its harder for them to get into, thats what I did.