Broody Hen pecking her own chicks?

[Chicken from the hood]

So my hen Cleo went broody 3 weeks ago I put fertile eggs under they just hatched today and she started pecking them untill they went back under her

I took the chick away and then she went back on the nest and started sitting again

Why is she doing this

Thanks.

 

[Jferlisi]

If i remember correctly, some hens will do that to keep the chicks under them to stay warm and they will usually stop when they get accustom to the chicks voice. Im not positive tho.

 

[Chicken from the hood]

Thanks I'll but 2 back under her, and see what happens.