Incubation refers to the process by which certain
oviparous (egg-laying) animals hatch their
eggs and to the development of the
embryo within the egg. The most vital factor of incubation is the constant
temperature required for its development over a specific period. Especially in
domestic fowl, the act of sitting on eggs to incubate them is called brooding. The action or behavioral tendency to sit on a clutch of eggs is also called
broodiness, and most
egg-laying breeds of
poultry have had this behavior
selectively bred out of them to increase production.