Parakeets (or budgerigars; click here to see the difference) originated in Australia. In the United States, it is common call a budgerigar a parakeet, although the former is technically correct. The scientific name for this species is Melopsittacus undulatus.
Because they were originally flock birds, they can be harder to tame than larger members of the parrot family. Budgerigars come in a varitey of color mutations such as green, blue, white, or yellow, but their original color is green. All other colors, therefore, stem from this green color. You can take the yellow gene out to make a blue parakeet or the blue gene out to make a yellow parakeet and so on.
They can make a good family pet, but more experienced bird owners, or those seeking extensive interaction with a parakeet must remember that as flock birds, parakeets are harder to tame. Training takes a lot of patience, and sometimes parakeets can learn to speak as much as larger members of the parrot family. The world record vocabulary for a parakeet was over 1000 words, but this is the exception and not the rule. You'll notice that each of your parakeets has its own personality, and is very affectionate towards familiar faces.
Adult parakeets usually range from 7 to 9 inches (head to tail). The tail is half of a parakeet's body length. Parakeets will amuse themselves and their owners by gnawing, climbing, playing with their toys, and most of all chirping. These birds have a wide variety of vocalizations and rarely stop chirping. Click the links to the side for more information.