They are going to peck at them, they have to put them thru the pecking order. If the younger group is at least the size of your smallest hen then they should be ok. Remember that every time they are taken away and then brought back it is new all over again for the older group. They need to be able to always see them even if they are seperated by fencing. Free ranging is the best way to get them acclimated to one another though because the smaller ones can get awayDans love the puppies the are growing so fast
Maidenwolf sorry about chicks I hope they pull threw.
I have been letting my younger pullets free range with current flock they are still chasing them & pecking at them. I haven't put the younger ones out in same coop/run yet is there something I can or will they just have to deal with it? I know someone showed a gadget to help with pecking does anyone know what it was called?