answersLogoWhite

0

Some hens will set during the collection of a clutch. This will throw off the hatch timing. Most hens will not actually sit on the clutch until she has enough eggs collected. 21 days is the incubation period, those 21 days are based on the day she first stays on the clutch. If you have a timed off hatch in an incubator, it is probably from opening the incubator too often and dropping the internal temperature of the eggs.

User Avatar

Wiki User

13y ago

What else can I help you with?