I'm curious if anyone else has had an experience like this. This spring we ordered chicks from two different hatcheries. We had 8 from one then ordered 6 from another, because the first did not have the breeds we wanted as sexed day olds. 11 altogether survived after 3 losses right after they arrived. Anyway, in the end the chicks hatched 2 days apart so they were very close in age. We brooded them separately because there had been some health issues with one of the hatcheries earlier in the spring. After a month or so we integrated the two batches. After a few minor squabbles they got along quite well. We did notice that the 4 that were 2 days older stuck together no matter where they were in the brooder. Didn't seem all that strange at the time. Then we moved them outside to the coop. They still stuck together in the pen. Then we let them out to free range with our older birds. Most of the time I can look out and the 2 barnevelders and 2 welsummers are close to each other, no matter where the rest of the flock is. At night, each and every night they are next to each other on one roost. I'd have thought by now they be truly integrated but they seem to want to be together. They get along with the other chickens when they're around. The others all mix throughout the day, hanging around with whichever chickens are nearby. Except at roost time. They all have their favorite spot!