Which class do birds belong to?

Birds belong to the class Aves, which is distinctly characterized by features such as feathers, a beak without teeth, and a high metabolic rate. Aves also lay hard-shelled eggs and possess a unique respiratory system that includes air sacs, allowing for efficient oxygen exchange. This class encompasses a wide variety of species adapted to diverse environments, highlighting their evolutionary uniqueness and ecological importance. Understanding that birds are classified under Aves helps in recognizing their biological characteristics and the role they play in ecosystems, such as seed dispersal and pest control. The other classes listed, including Mammalia, Reptilia, and Amphibia, contain different types of organisms, each with their own distinct traits that do not apply to birds.