Assuming those are fungus gnats, be careful, because in larger amounts they absolutely CAN cause problems!! My first grow I was overrun by them and after some time, they eat away at your root hairs and can cause some debilitating issues to your girls. In small numbers they are usually harmless, but looks like u may have a couple more than a few.. my suggestion, which has 100% eradicated both of my fungus gnat infestations... Azamax. About 14 ml/gallon. Lightly drench top layer of medium. 36-48 hours later, they will be flying all around your room as they can no longer survive in your damp medium and within 3-4 days, not a single sign of one remains. Good luck!!