didn't hatch all the way through

[AceODST]

I just hatched my first batch of my own bred eggs and had a surprisingly good amount of fertility despite my one rooster and twenty hens... a seemingly odd number of eggs were pipped but didn't break the shell all the way around. The due date was three days ago and I'm about to take them out of the incubator.

I guess what I'm asking is what are the possible reasons that they didn't break the shell the whole way? I know one isn't supposed the help them out but you can't stop me, but how do I get the bad numbers down in the future?

 

[sumi]

Failure to hatch at this late stage is most likely because of incorrect humidity or temperature in the incubator. What was your humidity and temperature during incubation and the last 3 days?

 

[AceODST]

55% temp 99-100 my thing doesn't have decimals

 

[sumi]

Did you increase the humidity during the last 3 days and while they were hatching?