Our girls regularly engage in a hilarious social interaction with each other that is very similar to that seen when athletes on a team score a goal or make a good play--they run up to each other, throw their heads back, and bump chests!!! This is often accompanied with feather ruffling and a bit of hopping about, but nothing overtly aggressive or nasty. They usually BUMP, then back up and go about their bidness. We have six pullets that are all roughly the same physical size: one white Ameraucana, one brown and white Ameraucana, one pearl black Ameraucana, one Brown Leghorn (now that's a beautiful chicken), one Golden Sex-Link, and one New Hampshire Red. They get along very well with each other. My wife and I are endlessly entertained by this little dance routine, but are wondering if it is the prelude to some serious dominance/pecking order action to come. There does not seem to be one dominant hen in the group. I guess that make me the rooster because they follow me around the yard and into the run. All of this chicken watching is pretty cool and entertaining at times.