After the embryo has developed fully in the egg, the young animal breaks the shell with its egg tooth from inside, creates a small opening, and for the first time fills its lungs with air. Afterwards, it pulls back into the egg and works on the shell with its beak until it opens completely. In nature, the animal remains below ground for the first two weeks, where it is safe from predators, yet is still able to grow, as it is nourished by the yolk sac. The young animals lead cautious and secretive lives, normally remaining in the shade. They avoid full sunlight because of the great danger of overheating.