Incubation question

[zabi]

Hi all,
I have a question on incubation... I am having a good hatch rate (atleast 95-98%) but my question is that when I do candling of the eggs, all my eggs are fertile and on the 18th day as I place the eggs down, most hatch, only one or two don't hatch but have fully grown chicks (I did crack open them 7 days after the 21 day period)... why is that so??? Humidity and temperature are always constant and also I do increase humidity slightly up for hatching.... thanks in advance

 

[Pyxis]

When you crack them open what do you see? Malpositions? A lot of liquid? There should be some indication of why they didn't make it.

 

[zabi]

When you crack them open what do you see? Malpositions? A lot of liquid? There should be some indication of why they didn't make it.

Nothing as such, just them dead... next time I will take more care when I do open, i might have missed the signs