I have two 8 week old chicks that are currently separated from my 2 other hens that are around 6 months old. When we first got the chicks I tried introducing them and one of my hens puffed its feathers out and tried to chase and peck at the chick. I want to combine the coops in the next few weeks so they can all enjoy the heater. Any tips or tricks to introduce to what seems to be an aggressive hen?