right i know this has been asked 1000s of times but my gold dutch bantams and red mottled leghorns are starting to come out of there eggs, i have a hovo bator incubator and im just wondering do i open the vents on top of it to let in fresh air, and how long do i leave the chicks in the incubator after coming out, there is 17egss left out of 42 only 17 were fertile