When a bird sits on its eggs to keep them warm as baby birds grow inside. Sometimes the male or female, or both, incubate the eggs. Incubation usually lasts for a week or more. Turltles and snakes will often bury their eggs to incubate underground by themselves.
To keep eggs warm so that embryos develop and hatch. The adult peregrines incubate the eggs by sitting on them. They also turn the eggs with their beaks from time to time. Incubation extends for 33 days.
To maintain (a living organism, such as microorganisms or a premature baby) under appropriate conditions, such as of temperature, humidity, or atmospheric composition, for growth; as, coliform bacteria grow best when incubated at 37° C..