When will the swallows return to the north?

Swallows return to the north from March to May. Swallows are migratory birds. They will return from the south to the north from March to May every year, where they will find mates, nest and multiply. They will migrate to the south for the winter from September to June, so they will return to the north from March to May every year. Swallow is a general term for 74 species of passeriformes, with small body, narrow wing tip, short tail concave beak, 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.