How to describe the sound of swallows?

Swallows chattered away. Swallows are singing loudly and hurriedly, singing, jumping, whispering, whispering and screaming.

Swallow is a general term for 74 species of passeriformes. Small size, narrow wing tip, short beak and concave tail, weak feet and few 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. 3 pounds per work? Seven eggs.

Swallow's hometown is in the north, which is very mysterious, so it was called Xuanniao in ancient times. The Chinese character "Yan" refers to the domestic swallow. Swallows are chestnut red in the front waist, with irregular horizontal bands in the back chest and milky white in the abdomen. Swallows usually breed from April to July. Domestic swallows nest under the eaves of farmhouses. Food is insects. Yan is a typical migratory bird. After the breeding, the young birds still follow the adult activities, gradually integrate into the large group, and move south for the winter before the first cold wave comes.