Day 24 and mamma hen is still sitting on 7 eggs. (UPDATE!!)

[GoldenSparrow]

Day 24 and mamma hen is still sitting on 7 eggs. Two hatched on day 21, but she keeps on sitting. Some of the eggs may have been placed under her a few days later after she started sitting.

Will mother hen leave if she feels no movement in the eggs? Or will she keep sitting on duds ?
How long will she sit and wait?

Is it bad for her? She doesn’t eat as much.
She loves the two babys, but she is still sitting, and wont leave the nest.

Should I take the eggs from her, but what if there chicks almost ready to hatch?

Thanks

 

[GoldenSparrow]

UPDATE!
we candled all the eggs again, and found that ALL of them have somthing in them. all very black.
but still no more have hatched.

would it be weird if all were dead? the eggs are completely dark.
if they are dead wont they rot or start to smell?

what is the succsess rate for a mother her?