It really is a valuable exercise to observe your flock at roosting time. I have fourteen hens in one coop and five pullets and a cockerel in a second coop. The fourteen hens are older, between six years and three years old. However, almost every night they have high drama at roosting, squabbling and shrieking like nobody's business. I have two curtains that I can drop that will divide the long perch into thirds. It's a life saver. It halts the fighting instantly. There are two other perches that are just six inches high, and they are very popular. Chickens, it turns out, love to have a choice.
In the other coop, I was finding the little cockerel, a Buff Brahma, on the floor. He often spent the night there if I didn't check on him at roosting time. When he was trying to roost with the girls, they would crowd at the end of the perch where he needed to hop to from a nest box because he's already too heavy to hop up onto the perch like the pullets can.
So I moved him next door into the rooster section where he has the entire perch to himself. But he still needs to use a nest box to leap to the perch. This is after I had already lowered the perches to just eighteen inches from the floor.
The rooster died a month ago of complications from a fall when he was trying to jump off his roosting perch.
It's always something, I swear. Roosting time isn't for sissies.