My chicks are now 2 weeks old. For the past couple of days they have been engaging each other in a strange dance. They charge each other with wings flapping and bump chests and then eye each down. Or they flap, fly and land on some unsuspecting member usually when their back is turned. There's a whole lot of squawking and posturing going on. I assume they are working out their dominance/pecking order. They aren't hurting each other but it is odd to watch. Is this normal behavior?