Sometimes I use those clear plastic or "clam shell" produce containers like the ones for strawberries, grapes, veggies etc. They already have ventilation holes and I line them with that grippy shelf lining. The larger ones can hold 1/2 dozen eggs or so. The smaller ones 2-3 eggs depending on size. I had pictures of how I set them up, but they are on my other computer. Works great for keeping track of individual eggs/chicks.