It is a process for them. They do grieve. I watched that last June after the eagle attack. Sorry if I'm repeating myself here, but I literally lost one of my original flock 3 days later from what I can only contribute to shock. Lucy has never been the same. She stepped down from top hen position, because she just isn't interested, but woe be to anyone who thinks they can outright challenge her. On the other hand, when I needed to integrate Alice and Abby, I knew I could trust Lucy to give them space in her coop.