"time out" for an aggresive chick worked..

I got a call from our post office at 4:30 p:m yesterday that our chicks were in. So we rush down to pick them up, all 6 alive and well, but when we put them in the brooder the fight was on. We had 2 chicks, a barred rock and gold sex link that we bought from Cal-Ranch a week earlier, already in the brooder, all pullets by the way.(I hope) The sex link was really cool, just checking out her new roomies, no aggression, but the barred rock went crazy, going to each new chick and wouldn't stop pecking them, the barred rock is only a week old but almost twice the size of the new chicks. She wouldn't quit so I put her in the box the chicks were shipped in for about 30 minutes and re introduced her to the newbies and shes been a model citizen ever since, no pecking or aggressive behavior at all. So I guess in her little chicken brain she thought she was the new chick when I put her back with the others and therefor wasn't agressive towards them? One of our little EE's

 

We have 2 EE's and 4 Australops plus the barred rock and gold sex link. The EE's are sooo cute,,well , actually they all are..