Incubation period

[Winsor Woods]

I know chickens have a 21 day incubation period. But I'm a bit confused...

Does this mean that they hatch on day 21? Or, do they hatch after 21 full days of incubation, thus day 22?

Also, when to the chicks inside the eggs start making peeping noises?

Dan

 

[Chickaholic]

I am wondering the same thing!!

 

[SundownWaterfowl]

hatch on day 21.

 

[UGAchick]

is the incubation period different for bantams?

 

[FarmGirl01]

My banties hatch at the same time as large fowl. Day 21. About day 19 you can start to hear pips and see the eggs rocking.