Is it normal behavior for hens to fluff up their feathers and chest butt each other?

Yes, it is normal behavior for hens to fluff up their feathers and engage in chest bumping. This can be a form of communication, signaling dominance, or establishing social hierarchy within the flock. Fluffing up feathers may also indicate that a hen is feeling threatened or trying to assert herself. Overall, these behaviors are part of their natural social interactions.