Great job at Chicken Juggling!
They wont really be one flock until the youngers start laying and working their way into the adults pecking order, so don't be surprised if the 2 age groups stay fairly separated most of the time.
Yeah, that technique often doesn't go well.
.....and 4 days isn't long.
How big is your coop and run, in feet by feet?
Dimensions, and some pics, would really help here.
Meanwhile, here's some tips on.....
Integration Basics:
It's all about territory and resources(space/food/water).
Existing...