they are fungus gnats.. they are hard to get completely rid of and they will keep coming back until you get rid of the soil that they been using to lay the eggs in... to save your plants until you can trash the soil, remove the top inch of soil carefully don't break any roots. replace that with clean play sand. that will keep the eggs that hatch from surviving. put a bowl of water with 2 tbls of apple vinager and 2 tbls of dish soap near the plants. it will catch alot of them, hang a few fly paper strips. but to be sure buy a mess of lady bugs and toss them onto the plants.. them little carnivores are the best pest preventives. they will end up hanging out on top of the sand waiting for gnats that hatch and make it past the sand. after i had them fucking gnats twice, lady bugs are what finally rid me of them. now use lady bugs all through my grow cycles. since then not a pest prob of any kind