full formed but not hatching

[wrfuzz]

We place 10 eggs in incubator for 18 days, move over to hatcher and only 2 chicks come out all the rest are fully formed but don't hatch. What is going on with these guys.
We place 8 eggs of another breed and 7 hatch.

 

[TweetyNPetey]

18 days? chicks take 21 days to hatch. Just place them back in the incubator and they will hatch in 3 days. maybe more or less.

 

[Roxannemc]

Could be your humidity was too low and they shrinkwrapped.You didnt tell the breed.Some have a fatal gene that can make them die before hatch.Think one might be Ameriacauna but not sure. A blue egg layer.