hey i breed these roaches. they're are very easy and breed fast! i have about 500 and i sell them now and have made about $120 in a month. that piggy backing is most likely mating but if you find the males that look like their wings are chewed off, its the females because they need more protein or more food more often. i find if you feed them more often the females wont eat their wings. and yes you should have multiple air holes just to get home sort of ventilation in there. and the little black bugs don't sound like the roaches because the babies (nymphs) are mostly grey. but i THINK they're nothing to worry about. but don't take my word on it. i have heard they come with feeder bugs especially crickets, but I've heard lizards and frogs can eat them. hope this helps