i candled some eggs my hen was sitting on to see if they were viable. she had abandoned them at one point but is now sitting strong. the egg shell apeared very porous and i could see a dark circle inside the egg like a yolk that shifted around when i turned the egg this way or that. i did not see veins but maybe my bulb was not strong enough? 100 watt bulb under an upturned flower pot. i declared them all dead. so then i cracked one into a dish to see what was inside and it was a little bitty black thing in a yolk full of red veins. so that seemed alive so i put the eggs back up under the hen who tucked them all under herself. can hens tell if the eggs are no good or will they keep on sitting and sitting forever or until a bunch of rotten eggs explode under her. ???
tried to candle eggs, what was i seeing?
yes, she knows! eventually she will push out what is dead or empty.
your candler just wasn't strong enough for dark porous shells, they are hard to see through. and be sure you are candling the TOP, the big end, that is where you will begin to see veins and the chicks eyes...
good luck with your hen! wish mine would go broody!
tf