Hen homies

I have the most thoroughly integrated flock of hens I've ever had, to date.  They hang together, closely.  I fact, I rarely count them anymore, because I'll see them as a group, in at most two not very distant packs, and know they're all there.  No more outliers or lone wolves (I know, I know- inapt).They have friendships and preferences; two or three will roll side by side and, say, stay out to the very last minute, or linger under the birdfeeder together, while other girls lurk on the dog's bones, but all of them are never very far apart, and usually surprisingly close together.This is odd because the current layers are from three sources.  The "old original hens" - the wise old survivors that grew up free-rangin', yo, the "co-op hens" - unfortunate clipped beaks, and no survival skills at all, and the "leftover hens" from the neighbour, the arrival of whom seemed to catalyze the new familial cohesion.I can tell the birds of various provenance apart easily.  The old birds are looking dull, and the leftovers are the darkest.Why are they so tight all of a sudden?I wish I knew.  They just like each other more now?As long as they're happy.