The order Psittaciformes is comprised of the parrots and their allies. They are found in most warm and tropical regions. The greatest diversity of parrots is found in South America and Australasia. Characteristic features of parrots include a strong curved bill, an upright stance, and strong legs. Like woodpeckers, they have 2 toes pointing forward and 2 toes pointing backward. Most parrots are predominantly green, with other bright colors. They generally exhibit little or no sexual dimorphism. The most important components of most parrots’ diets are seeds, nuts, fruit, buds and other plant material. Almost all parrots nest in tree holes. Parrots are some of the most intelligent birds, and the ability of some parrot species to imitate human voices enhances their popularity as pets.