Answer: Three weeks
Notes: A hen that is committed to hatching chicks is known as a broody. The state of being broody is controlled by instinct, hormones and lighting conditions. Chicken come out of the eggs within the 21 days after being hatched by the hen. Some breeds take a little less and some a little longer. If the egg has not hatched after 25 days, it should be removed from the broody hen or incubator. Eggs need constant heat during the full incubation period for the embryo to develop into a chick.
