yup they sure do. they will find their way in... I had nightmarish time with the gnats this time around and only because of them stupid smart pots keeping the bastards alive... once they are an issue in them next to impossible to rid them.. I heard several things regarding that, that I kept my coco to wet, or my coco was infected, blah blah but no it wasnt infected, my coco wasn't too wet... I know exactly how it got in, only takes one to make millions.... once they are breeding on them smart pots, you won't get rid of them using sprays,chemicals or anything else..