Hiccup has been with us for just over a year. We adopted him from a nearby bird shelter. He was generally easygoing up until about a month ago. I had cleaned his cage very thoroughly, giving him new toys. I installed a little heater and we finally got some lights up over his cage. He seemed to get impatient with me and attacked my neck, biting me really hard. He hadn’t done anything like this before. He has since tried to attack me and my spouse if we opened his cage to hang out. He attacks the cage if either of us come near. I have marks on my neck from his most recent expression of displeasure. He used to hang around while we prepared bird breakfast and because of his behavior change, I haven’t felt comfortable letting him out. Do Quakers have a hormonal period? I knew he was cage protective, but my lack of understanding is killing me and I hate leaving him in the cage like this. I felt like we were all settling in and getting to know each other better. I’m tempted to turn his lights off. I read the articles posted in the hormonal post. The descriptions sort of fit, but the articles seemed directed towards Zons, Toos, and the larger companion species. Any experience, strength, and or hope is appreciated.