Twice today, I saw my smallest pullet (she's 12 weeks old), Betty, charging a Robin in our yard. Of course the Robin flew away, so there were no chest butts, or stretch and fluff contests! Betty is the smallest in my flock of six, but she's also the most fiesty. All my girls get along really well, so far, so nobody gets picked on, but I'll bet Betty was hoping to win the "I'm bigger than you are" challenge for a change.