Is it absolutely necessary to candle eggs of mom is hatching them? Or will she kick out any "bad" eggs? I've never candled before, she's been sitting for two weeks now
No, its not necessary. I doubt she will kick them out, at least mine never do, but I've never had a rotten egg explode without it being cracked or something. However, you can candle them once on day 14 to see if there are any quitters, then toss any you are sure are dead or infertile.
Best of luck!
