Why humidity?

[emsdial911]

Why do you need humidity in the incubator?

 

[Glenmar]

To keep the incubating eggs from loosing too much moisture. And at hatching to keep the membranes moist so your chicks don't shrink wrap and die.
Humidity is very important.

 

[cmom]

The humidity keep the membrane in the egg moist so the chick can turn as it pips then zips.