My chicken has this sac on her head that feels as if there was air or water in it. It does not feel like a tumor and is slightly squishable. It's almost as big as a quarter in diameter and doesn't seem to be bothering her (still lays eggs and behaves normally), so is this something I should be doing about this or just let her be? And does anyone have any idea what this is?
she blinked for the picture
she blinked for the picture
