Thanks for sharing the article. I checked the air cells of the marans I have, and I can't see them. Any suggestions?Best to keep them straight up so that the air cell hopefully ends up where it is supposed to be. Read this article: Hatching shipped eggs lots of good information. You really only want the temperature to swing about a degree either way. Any more than that and it will affect the embryo. The first 7-8 days are most important at keeping the temp at a steady 99.5. When you first put yours eggs in the bator there will be a temperature decrease because the eggs are "absorbing" the heat to get up to temp. After a few hours you can start making small adjustments if the temp is still off.