OK I broke down last night and tried this on 30 eggs I have in the bator. Some I am not sure if they are developing most I know are. I hope its not right or I have about 75% roosters. A few would never do the circles or sway, maybe these are my questionables. I put marks on and will candle them in a day or 2 didn't want them out of the bator that long. Good news is if this is even 75% right I can try it on the eggs when we collect them and know which to eat and which to put in the bator.
I just can't figure out how to tell who is who after they hatch without marking them as soon as they hatch which wold mean opening the bator, I need another bator to put the possible girls in 1 and boys in the other. But hey this is another experiment for the kids science right, so hubby can't get to upset.