Yes if they are gnats, they will eat the organic matterlike roots and soil. I tried to get control of them with mosquito bites, but never got control. They multiply very quickly. You can put sand as a top layer and water from the bottoms. Butt chugg as some call it . Not to scare you but I never had any luck. I think there were too many before I noticed them. You got to love buying dirt with an insect farm in them. I hate those fuckers so bad I went to DWC and have not looked back. We have them bad here in the south. Others may have success fighting them off hopefully they will chime in. Rabbit might have some good ideas.