I had 4 chicken, 3 duck, and 8 guinea eggs in my incubator which were all due to hatch this past Monday (I added the ducklings earlier so they'd all hatch together). I had a 100% hatch rate for the chicks and ducklings. All hatched a day early on Easter and the third duckling hatched last night. ...BUT there are no signs of piping from the guineas. I bought them online and was starting to wonder about the fertility. I had a hard time candling them because of the dark shell (i just ordered a GOOD candler) but from the little I could tell, there was a good size "dark spot". I decided to break one egg open to see if it was even alive or I got ripped off. THERE WAS A CHICK INSIDE and it's breathing, but not moving very much. I left half the shell intact and put it back in the incubator to see if it'll continue hatching on its own. This is our first hatch of guineas. The shell was VERY hard. Is that typical for guinea eggs? Or do I need to adjust the humidity? (I have a thermometer but not a humidity reading) My question........should I break open the other eggs too? OR how much longer should I wait? Someone please advise soon so I don't lose any!!!