We have 6 EE's (at least we were told they're EE's) that are about 11 weeks old. We got them when they were 10 days old. They've lived in a brooder in our basement until 5 days ago when we moved them to their new coop. They seemed fine with the move, but 2 days ago one of them (named Trouble) bit my wife on the hand while she refilled their food. Then yesterday morning Trouble bit me 3 times, and her twin bit me once. I responded to each bite with a tap on their head. The other 4 girls are very well mannered, as they've always been. I'm wondering if Trouble and her twin (named Poopy) might not be EE's. I know EE's are mixed breed, so maybe the breeds of these 2 include some more aggressive birds. Or, maybe they're not EE's after all. You can see in them all in the picture. 3 of them are chipmunk colored, 1 is blue/wheaten, and the 2 white birds are Trouble & Poopy. Their personallities seem to be grouped accordingly as well. Trouble has always been the most adventurous of the bunch, followed closely by Poopy. They've always been the most demanding of our attention, wanting to be near us, and held. We've hand fed treats to all of them without any issues. This morning Trouble tried to bite me again, so I did what I read on this forum. I scooped her up and held her upside down by her legs. It didn't seem to bother her much, she just hung there making quiet sounds. After about 20 seconds I put her down. She immediately got up, puffed up all her feathers and tried to bite me again. I held her upside down again, this time until she squacked. When I put her down Poopy ran to her and pecked her on the head several times. 15 minutes later my wife went to the coop to say good morning to the girls, and Poopy bit her. We'll continue trying to correct their behavior, but I'm wondering anyone knows why they've started getting territorial now. Maybe I'm just crazy for trying to make sense of chicken psychology.