I have 2 age groups of pullets. My older group of pullets (almost 3 months) consist of 2 EE, 2 RIR, and 1 Blue Australorp. I added 2 more -- another Blue Australorp and a Barnevelder who were besties before I added them. Recently I added some more younger pullets -- 3 Black Australorps, 2 Barred Rocks, and 1 Lavender Orpington. Recently the Barnevelder who has been joining up with the black Australorps. That made me wonder if it was joining them because they look similar? I then realized my EE (who look the same) are best friends, my 2 RIR are best friends, and the new Blue Australorp has started hanging around the other Blue Australorp. Do chickens like to hang around others that look the same? It's so interesting that the best friends (Barnevelder and Blue Australorp) split up and are hanging around chickens that are the same color. Coincidence?