With all these studies and fretting over incubation temps/humidity/turning sometimes I think, it's amazing that hens do it all the time.
I wonder when the last time hens had their thermometers and hygrometers calibrated!
I'm just laughing because I'm one of those people with 4 thermometer/hygrometers in my 'bator and I check them every chance I get as I wonder just what is going on in those eggs and if everything is OK.
If I could put a little window in the egg shell, I totally would.