Can hens tell fertile from non-fertile eggs?

[heavenzeyes]

I have a 8-10 month Australorp hen, in which my daughter bought for me a few months bk. She was immediately accepted into tha flock by the others. It didn't take her long at all to choose her Rooster or vise versa. Either way her Rooster is a White Crested Polish Chicken & both of them are INSEPERABLE. Last wk she started layin eggs, every day she's layed 2 /day. As of the time of this post she's layed 16 eggs thus far! I couldn't help but ta take notice the absolute ONLY time she'll ever be seen in the nesting box is just moments before she lays an egg. She lays an egg, will cluck several times over to announce it to everyone, then off she goes. When tha coop is locked up at nite she'll roost on the roosting branch & other flock members will roost on the SIDE of the box. Every nite I've switched places between them all, put her on the eggs & the others on the branch, yet a few moments later I hear her hopping onto the branch. Early morning she's on tha branch & ready ta take off fer tha day. Her Rooster seems to favor roosting underneath tha box while she will roost above tha box. Yet none of any flock members will sit on the eggs!!...Is it possible that she may very well be aware as ta if they're fertile or not? I've candled tha very first 2 eggs she laid 1 appears non fertile & the other a lil questionable. Have any chicken hens been known to wait until they've reached a certain amount of eggs before sittin on them, just like ducks?
At what day is tha best day/days ta candle after being layed?...I started tha candling on the 3rd day after the first eggs were laid.

 

[littlemissbatam]

hens lay for like a month or less but it doesn't mean she's going to sit hens sit when they want babies

 

[heavenzeyes]

well we were all hopin ta keep tha first clutch of eggs layed & then use each additional clutch until fall of next yr. However we haven't any incubators & really dnt wanna do it ourselves. We wanna rely on tha hens themselves. I guess if they dnt want any babies as of yet then to tha kitchen they will go until she or any of the other hens are wantin babies. Somethin's tellin me, I dnt think this hen will ever want babies.
Thanks a bunch this really helps us out.

 

[littlemissbatam]

Ya but if A do plan on incubating get the incubator get it on eBay l got my for about 48 dollors on there

 

[MySweetChickens]

So ok from what I understand the hen is in front of the nest but refuses to sit on eggs and like the other poster said she will only set if her hormones spike enough to tell her too. But you need to keep in mind eggs will not develop unless kept at incubating temperature meaning there is no way you could of candled the eggs to see if they were fertile unless you incubated them or cracked them open to look for a bulls-eye. I'm guessing that is what you did if so eggs with a circle within a circle on the yolk means they are fertile. It's also worth mentioning that eggs lose their ability to develop a embryo if they are kept dormant too long.