Hummingbirds

Hummingbirds are the smallest birds in the world.

An excerpt from the article 15 facts about hummingbirds

The smallest species of hummingbird is the bee hummingbird (Mellisuga helenae), which does not exceed 6.3 cm in length, of which the beak alone reaches 1.2 cm in length. The largest of the species is the giant hummingbird (Patagona gigas), which can reach 23 cm in length.