Do chickens prefer round or flat perches?

Excuse me, but I'm curious about something. The paragraph you mentioned talks about chickens and their preference for perches. Now, I understand chickens need places to rest and sleep, but does it really matter whether the perches are round or flat? I mean, isn't it more about the comfort and stability they provide? Or could there be a specific reason why chickens might prefer one shape over the other? I'd love to hear your thoughts on this.