I would'nt use them in my colony dubia are'nt the cheapest. If your having a hard time finding unused egg flats try cup holders from a fast food place near you i started with cup holders from Mc'Donalds i just asked to buy some from the manager after ordering my food and he just gave me 10 for free then the next time I asked some one at another fast food place. Cup holders work just as good and since you only have to change the cup holders or egg crates once a month or so depending on the size of your colony they last. With cup holders placed flat along with tp and paper towel rolls and my colony bred fine they just need cover for hiding and to feel safe eating and moving from hot to cool sides of your bin. I hope this helps.