humidty manipulation and turning, hen does not seem to change

[centrarchid]

I hen incubate and use an incubator. Highest hatch rate from hens (>95%) while incubator yeilds lower (~80%0. Hens do not seem to manipulate humidity. I am not certain but I think they still turn eggs even after day 18. Why am I investing so much in controlling humidity and stopping of egg turning yet hens out performing me?

 

[Ridgerunner]

In my opinion, we are trying to artificially recreate a natural process. There is probably more to incubation than temperature, humidity, and turning. What, I don't know. Maybe she communicates with the embryo? Maybe the oil on her feathers affects the developing chick. Probably something else entirely. But, yeah, my broodies outperform my incubator.

Editted to add:
Perhaps a broody gives them better air exchange. Who really knows the difference?

 

[teamsunbelt]

Tell me one thing that a man can do better than what God invented. Chickens did not survive all of these years by relying on a human to hatch for them. I would be surprised if someone could incubate on a regular basis what a hen does, especially if you get greater than 95%.