Cockatiels that have been hand trained as babies are delightful and busy birds. They are gregarious. In nature, they live in large groups and stay together.
They play and will follow you around. They love to eat and will eat a lot of things not listed in bird care books.
Cockatiels are about 14 inches from stem to stern. They are easy to care for and do make a mess. Stuff like seed shells fly out of the cage. It is worth ever bit of effort to keep and care for a Cockatiel.

Six pictures. All from Wikipedia Commons.

By Jonrev

By Jana

By, Magalhaes

No name given

By, Jana

The last picture is by, Zandperl.