HI RIDGERUNNER, & THANK YOU...!! YES I TO NEVER HAD A MIXED FLOCK BEFORE..? .....lol.... so this color thing is nuts to me.....lol... it could be the age difference..?a differance of 4 weeks..???? between the reds & the blacks & yes we have something like sudden skirmishes, from 2 red ones who are always together & turned aggressors since tiny chicks...?? geezzz..??? and then 2 other reds both girls they are mostly fine with the blacks, no real skirmishes from them, we have 4 red ones & they are the older ones by 4 weeks & one possibly is a young roo..? he is very sweet with me & all the red ones , THE BLACK ONES ARE 4 barrdrocks 12 weeks & 7 silverlaced whydandotts 9 weeks who live together very well since they were tiny chicks, but they all have been separated after they were all just purchased,& all at different ages, the reds were 4 weeks , I got them first & much bigger then the blacks who were all still tiny fuzzzz balls just days old....lol.. all to small for the reds jumping on them , so since we got them all they have been screen separated and can see each other constantly , and all in good size space for each group, also all are being air conditioning until they get a lot older or the AZ weather is less hot, I would not stress out growing babies in the heat of AZ , they could die...!!! so they all come out to run and play all together with me every day for hours before sun set, when its cooler then here in southern AZ & they all stay out until they want back in, but play time is when 2 reds turn aggressors, and charge into the younger smaller black group ,but they turn back when i tell them to..! and mostly they all stay separated its like they choose to do that on their own..? by staying on either ends of their play area .? but the reds do try to run into the blacks, i figure that letting the smaller younger ones grow a lot more in size when they are a lot older and after i train all of them to come running to me if i see any kind of danger..? they will all go out together in the open yard of several acres and then let it all happen in the pecking order between colors that will eventually take place , so thats my plan....lol.. I have trained my chickens in the past but all were the same breed young hens from the live stock action , so im a bit amazed by this red / black thing...?.....lol...plus i never had tiny peeps with out a mother hen who raised them ...??????..lol.... .