I don't know whose swallow it is. It is taking soil from the ground to build a nest. Usually in spring, a large number of swallows will go out to grab soil and strengthen their nests. When building a nest, swallows peck the soil into balls through their beaks, and then use countless balls to build a nest. The word "peck" is used in this place, which can vividly and truly show the scene of swallows nesting. At the same time, it expresses the pleasant landscape of the West Lake in early spring.
This sentence comes from Bai Juyi's work "Qiantang Spring Tour" in the Tang Dynasty, which depicts the characteristics of the West Lake in early spring. Combined with the whole poem, this sentence mainly describes one of the scenery of the West Lake, that is, the scenery of swallows nesting, and expresses the wonderful scenery characteristics of the West Lake in early spring.
Extended data:
Swallows like to nest under beams or rafters. After choosing a place, the male swallows help the female swallows with mud. They fly to the place where there is water, fill up the mud with their beaks, bring it back one by one, to the point where they can pick it up and pile it up into a dish-shaped nest.
Swallows generally choose to nest under the eaves where the wind can't blow, the rain can't rain and the walls can't be too smooth. Like a wall with tiles, few swallows nest. And if there are some iron wires, lamp holders and other things that are convenient for them to nest, it is often easier to attract swallows to nest.