I have a 7 egg incubate. Put four in the beginning of September and three more eggs in a few days later. I use to think it is 21 days but it is more like 19, and yesterday the first 4 hatched out. The incubator is kind of small and since I had it set for 21 days it was still turning the eggs. The first three sat on the last hatching egg while it was turning and the hole was left on the bottom. The membrane dried out and I had to help the last one a little bit. But the chick seems okay. Someone told me today that 99 degrees will make roosters and 101 degrees will make hens. Can any one give any truth to this? As far as I can tell by the feather sexing they're all roosters. Going back and taking a second look.