GARNIZÉS - Galinha matando pintinhos / Hen killed her babies!

I never had a hatch with 10 chicken babies. It´s the first time, I was really surprised.
But today happened something sad I never saw before.
The ken attacked her babies and killed one!
I don´t know the reasons yet. I will investigate and tell you!
Now the 09 babies were taken out from her, unfortunatelly!
If somebody knows the causes, please, give me the informations in the comments that I public here!