I would like to add some different colored birds to my flock.... I already have RIR, Buff Orp.,Dom mix, WR/BR Mix and A white EE. I would love a Black chicken and some multi colored chickens. I have heard that some can be aggressive and nasty. I have a 7 year old that helps with my birds so I need nice girls......I have been looking on the different web sites and I wanted to hear from real bird owners.... Any suggestions?