Precocial birds hatch with their eyes open and are covered with downy feathers that are soon replaced by adult-type feathers.[1] Birds of this kind can also swim and run much sooner after hatching than altricial young, such as songbirds.[1] Very precocial birds can be ready to leave the nest in a short period of time following hatching (e.g. 24 hours). Many precocial chicks are not independent in thermoregulation (the ability to regulate their own body temperatures), and they depend on the attending parent(s) to brood them with body heat for a short period of time. Precocial birds find their own food, sometimes with help or instruction from the parents.