I've posted a few times about this topic and heard several different oppinions......So a couple of days ago, I decided to integrate all the chicks. I have almost 2 weeks olds in with 5 day olds and it's been a success so far. Very little pecking and they all play and sleep together, I'm glad I got them this soon so they can grow up together...the little ones actually enjoy tagging along and sleeping with the older ones! I was so worried but now I'm so glad!Just had to share, Thanks.