Lucky is attacking the new chicks

[LuckysMom]

My eight little bantam chicks are old enough to go out in the coop now, (they are about 4 weeks old) so I took them out there Sunday night. I left them in the dog cage they've been living in, inside the coop. I gave it a day for Lucky to get used to them being in his coop. Then yesterday I let the biddies out of the dog cage. All was well for a little while, they were just checking each other out. Then one of the little ones puffed up at Lucky and Lucky grabbed it around it's neck. I broke up the fight. But now whenever the chicks are out of their cage, Lucky chases them around and pecks at them, even if they are not being aggressive towards him. I had to put another dog cage in the coop to lock Lucky up in so I can let the chicks out to get some exercise sometimes.
Is this something that they will resolve themselves as the chicks get to be Lucky's size? Is there anything I can do to help them adjust to each other? Should I just keep them separated until they are all the same size? I got these chicks so Lucky would have some company but it's sure not working out that way.

 

[akcskye]

Billy had the same issue with Marti and another chick we had named Snowy when they were little.

He was QUITE a bit larger than them, and when we'd put them in with the girls, all would try to attack.

Snowy eventually died...we think a hawk got her...but Marti lived, and though still obviously at the lower part of the pecking order...Billy accepted her fine once she was old enough to lay...guess when he realized she was another girl to "claim", he had no arguments with it! haha