Certain species have lengthy tails and wings, and their wingspan is rather small. Their little beaks are surrounded by bristles in the majority. The toes are somewhat webbed, and the legs and feet are small and feeble. A comb-like pecten on the inner edge of the middle toe's claw can be utilized to care for feathers. The plumage has a cryptic brown and grey pattern.

There are others that are the tiniest known living birds, the hummingbirds. Their bodies are small, and their wings resemble blades. Their anatomical structure allows them to fly like helicopters in all directions, even hovering. Their feet have three toes facing forward and one backward, called the hallux, and their legs are small and lack knees. They also have extremely specialized feathers and iridescent colors.