I have a flock of 23 older hens (3 - 4 years old). I also have a flock of 23 younger hens + one rooster. The younger flock is in a large building with enough room for all 48 chickens. How do I merge the two flocks with out bloodshed? There is only the one rooster. I am not sure this matters, but my older flock used to use the big building. I built a new "garden coop" so they could weed my garden all winter and spring. I don't know if they will remember the new building or not. Any help will be appreciated. Thanks.