One dud egg

[Bean15]

I noticed this egg had a boodring when I candled it this morning. what could have been the cause? A few nights ago, my humidity spiked up to 70% but only for an hour or so. The other eggs seem to still be growing fine, and I'm starting to see heartbeats. Was this the cause of the poor chick's death, or was it just a dud?

 

[Clearwater Chicken]

I don't know the cause of death but a blood ring is caused after the embryo dies and the blood vessels start to decompose, i may be wrong but to my knowledge this is what causes a blood ring

 

[Bean15]

I don't know the cause of death but a blood ring is caused after the embryo dies and the blood vessels start to decompose, i may be wrong but to my knowledge this is what causes a blood ring

The weird thing is, I never even saw an embryo! it was completely "empty" one day, and then the next, it had a blood ring. weird.

 

[Clearwater Chicken]

embroys when they die at 2-3 days are near invisible