Animal eggs are reproductive structures produced by female animals, containing a developing embryo. They come in various shapes, sizes, and colors, depending on the species. Common examples include the eggs of birds, reptiles, and fish. The egg provides nutrients and protection to the embryo until it hatches. Most animal eggs have a protective shell or membrane that helps keep the embryo safe from environmental factors. The process of laying eggs is called oviposition, and it varies among species. Some animals, like frogs, lay thousands of eggs at once, while others, like birds, typically lay fewer eggs in a single clutch.