What is the metaphor of swallows?

Swallow is a metaphor for returning from overseas; Candles are metaphors of selfless dedication; Pigeons are metaphors of messengers of peace.

Swallows are small in size, narrow in wing tip, short in beak, concave in tail, weak in feet and few in feathers. Feathers are monochromatic, blue or green, with metallic luster; Most kinds of men and women are very similar.

Swallows spend a lot of time catching pests in the air. It is one of the most flexible birds, mainly feeding on insects such as mosquitoes and flies, and is a well-known beneficial bird. Nest in tree holes or cracks, or make holes in sand dikes, or stick mud on walls or protrusions of corridors, roofs, eaves, etc. In urban and rural areas.

Extended data:

Swallows are beneficial birds for human beings, mainly feeding on insects such as mosquitoes and flies. A swallow can prey on more than 500,000 pests and protect crops in one summer. Swallow is a famous summer migratory bird in China. Migrate to the north in early spring and spread all over the country in summer. After breeding, they move south in groups and overwinter in India, Nanyang Islands and Australia.

Swallows feed on insects, and have always been used to preying on flying insects in the air, but they are not good at searching for insect food in cracks in trees and on the ground. They can't omnivore berries and seeds like grouse and Thunderbird, eat leaves in winter (some conifers don't shed their leaves even in winter), and they can't dig up larvae, pupae and eggs of latent insects like woodpeckers and woodpeckers. There are no flying insects for swallows to prey on in winter in the north.

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