Smallest organisms
With a mass of approximately and a length of 5 centimetres (2.0 in), the bee hummingbird ("Mellisuga helenae") is the world's smallest bird species and the smallest warm-blooded vertebrate. Called the "zunzún" in its native habitat on Cuba, it is lighter than a Canadian or U.S. penny. It is said that it is "more apt to be mistaken for a bee than a bird". The bee hummingbird eats half its total body mass and drinks eight times its total body mass each day. Its nest is 3 cm across.
Vervain hummingbird
It is considered the second-smallest bird in the world after the bee hummingbird. Typical length is 6 cm (2.4 in), including the bill, and weight is . It also has among the smallest eggs in the bird world, with an average length of 1 cm (0.39 in) and weight of 0.375 g.