hi smoothe,i take it that you are growing in soil,if so it's sound's like scarab fly larvi,this usually mean's that your soil is to wet,as they live in the damp just under the suface.let your plants dry right out until they start to wilt,then water them again,not lot's about 400ml per plant,then keep an eye on them only water when they need it,it mean's more watering but the larvi don't get time to mature..but if you have a few still living they don't seem to do any harm,or the fly's they are like little black knat's...anoying but pretty harmless...hope this help's love an respect spliffbuilder.