Older chickens terrorizing younger ones?

[Pequena Bandada]

I have four 9 month old pullets and eight 10 week old chicks (9 pullets and 1 cockerel). They all live in one coop, but I have a chicken wire wall separating the two groups. They have separate doors to the run, which is also divided in half by chicken wire. Two of my older pullets absolutely terrorize the younger chickens. They run at the wire making growling noises and on the rare occasion when they can get into the baby pen they chase the chicks all over the place. They cornered and pecked my adorable little Salmon Faverolle yesterday before I realized that they had gotten into the baby pen.

Is this ever going to stop? What will happen when I integrate the two groups? I could use any advice from experienced chicken owners about how best (and when) to integrate the two groups. Once the babies get bigger will they suddenly decide to defend themselves?

 

[abhaya]

once the babies get bigger it will stop just keep them seperate for now