We were hatching 7 shipped eggs, bantams, silkies and sizzles. We tried the Styrofoam egg carton method. cut out the bottoms and positioned the eggs with the air sacks up, big end up. We had 2 successfully hatch, sizzles. A Silkie pipped and zipped at the same time as the sizzle in the egg carton next to it. Humidity was about 55 %. The first to zip practically jumped out of it's shell, and climbed over the other eggs and started running around and peeping loudly. The second sizzle was assisted by the first sizzle and part of the egg shell-the bottom-was stuck to his bottom for a couple of hours. The Silkie seemed to be struggling to remove the egg shell, a Sizzle tried to help but ultimately gave up and helped the other sizzle. The Silkie was peeping. The Silkie shells were very thick and not very porous on candling. The Sizzles had more porous shells. We let it go about 1 1/2 day but when we didn't hear peeps for a while, we decided to remove the Silkie egg. It was partly attached to the Styrofoam egg carton. It was unable to completely zip I believe due to the thickness of the shell. We removed the shell to find a perfectly formed white Silkie, totally absorbed yolk sack, just perfect, broke our hearts. Another Silkie pipped and zipped after these first 3 pipped. This was successfully a beautiful black Silkie chick. What we learned from this, the egg carton method is great for more porous eggshell hatches. The thicker the shell, the more possibility of the chick becoming stuck and shell attaching to the Styrofoam. Perhaps the higher the humidity causes the thicker shelled eggs to adhere to the Styrofoam faster. We have 3 more eggs with little ones inside at Day 23. No one has peeped or pipped. I've just moved the eggs out of the Styrofoam carton onto the grate. Of the 3 remaining eggs, only the Silkie egg was "stuck" onto the Styrofoam. For incubation a couple of the eggs were older, 9-10 days old, 1 egg in this hatch was 5 days old. Not sure how viable they are due to egg age but want to give them another few days to try to hatch. I would say, watch for the thick shells, let them lie in a different container or on the grate. Styrofoam egg carton is best for more porous shells and fresher eggs. Hope this helps someone's future hatch!