The entire process is under
The entire process is under the control of the hen's pituitary gland. This gland is actually the
mastermind of almost any animal. First, it stops producing the hormone that induces egg-laying. Next it sends out another hormone that causes several other
glands to go to work. This causes one to produce increased Seretonin which is the same results you or I would get from taking the popular drug Paxil.
My hens are broody.
originally posted by judlew