Mobile Egg Office

An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, mollusks, fish, and monotremes, an egg (Latin, ovum) is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing embryo can survive on its own.
Oviparous animals are animals that lay eggs, with little or no other development within the mother. The study or collecting of eggs, particularly bird eggs, is called oology.
Reptile eggs, bird eggs, and monotreme eggs, which are laid out of water, are surrounded by a protective shell, either flexible or inflexible. The special membranes that support these eggs are traits of all amniotes, including mammals.
Eggs laid on land or in nests are usually kept within a favourable temperature range (warm) while the embryo grows. When the embryo is adequately developed it breaks out of the egg's shell. This breaking out is known as hatching. Baby animals which have just hatched are hatchlings, though standard names for babies of particular species continue to apply, such as chick for a baby chicken. Some embryos have a temporary egg tooth with which to crack, pip, or break the eggshell or covering.