Parrots are one of the most intelligent of all birds and their ability to mimic human speech makes them popular as pets. The order of Psittaciformes (parrots and cockatoos) includes more than 350 species. There are more than 60 genera, and each type of bird differs in size, colour, and behaviour. Some types of parrots are critically endangered, like the kakapo (Strigops habroptila), with fewer than 150 left in the world.
 
 In the wild, parrots nest in tree hollows or in nest boxes in captivity. Many of these are natural cavities, but some are made of twigs, branches and other materials. They lay white eggs, which are incubated by the parent birds.
 
 The most common parrot nest is a cup-shaped structure, often seen in the fork of a tree or bush. The nest is made from twigs and grass stems, with mud, moss, leaves, feathers and other material woven into the cup. Some bird species use glue made from saliva to hold the nest together. Willie wagtails are clever at this, gathering grass stems and "sewing" them together with spiderweb that they stick to using their sticky feet (or zygodactyl, which have four toes that point forward and two toes that point backward).
 
 Other types of parrot nest include flat nests built from twigs layered on top of each other.  https://nestvui.com/bang-gia-to-yen-sao/  have the advantage of being easily accessible, but may not be very secure. Some bird species, such as robins, thrushes and blackbirds, will add pieces of paper or other material to these simple nests for additional strength. A variety of other birds, including magpies and crows, make similar nests in their own ways.
 
 Those interested in encouraging native birds into their gardens can help by providing piles of sticks and other materials for them to build nests from. Old wire-mesh suet cages can be filled with material and hung in the garden for potential nesting birds to push into crevices. An empty kitchen whisk can also be used to create mud, allowing birds to construct nests in bare spots in the garden or on the ground.
 
 Parrots that are kept in aviaries will often use wooden nesting boxes, which are mounted high on the side of the cage to replicate tree cavities. Care should be taken when opening the inspection door of these boxes, as removing young birds from the nest prematurely can disrupt the laying cycle and result in them leaving the aviary too soon.
 
 Edible bird's nests are prized in some cultures, especially China, where they are soaked to extract a fluid that is used as a health tonic and soup ingredient. The nests contain a host of nutrients, such as carbohydrates, glycoproteins and fatty acids.
 
 Although most species of parrots live in warm areas, there are some cold-weather parrots, such as hyacinth macaws and thick-billed parrots. The nests these birds make are small and tightly packed to increase the success of properly incubated eggs.