Again why I hate crickets. I clean the dang bin out every week and clean out dead crickets daily. The ventilation is good. But no joke I kill probably 6 a day in that tub and there's always a black sludge at the back where I keep the egg trays. Everyone else I know doesnt have this issue... I gutload with sweet potatoes, cellary greens, oranges and mangoes and The bio dudes cricket gutload. Maybe they're eating too much wet foods? Not sure, I feed my dubias the same thing and I dont have this problem whatsoever.