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.
White-toothed shrew
The outer layer of these shrews' teeth is white, unlike that of the red-toothed shrews. These species are typically found in Africa and southern Europe and Asia. This subfamily includes the largest shrew, the Asian house shrew ("Suncus murinus"), at about 15 cm in length, and the smallest, the Etruscan shrew ("Suncus etruscus"), at about 3.5 cm in length and 2 grams in weight. Shrews are possibly the world's smallest extant mammal (although some give this title to the bumblebee bat). "Crocidura" contains the most species of any mammal genus.