Hummingbirds are native birds of the Americas and constitute the biological family Trochilidae. They are among the smallest birds, most species measure 7.5-13 cm (3 – 5 in.) long. In fact, the smallest species of bird in existence is a hummingbird, the 5 cm (2.0 in) Bee Hummingbird weighing less than 2.0 g (0, 7 oz).
They are known as hummingbirds due to the buzzing sound created by their wings beating that flap at high audible frequencies for humans. They float in the air at fast hitting speeds, ranging from approximately 12 beats per second in the larger species to more than 80 in some of the smaller ones. Of the species that were measured in wind tunnels, their maximum speed exceeds 15 m/s (54 km/h; 34 mph) and some species can be immersed at speeds above 22 m/s (79 km/h; 49 mph).
Hummingbirds have the highest metabolic rate of specific mass of any homeothermic animal. to conserve energy when food is scarce, and nights when not For Rajan, they can incorporate torpor, a state similar to hibernation, slowing the metabolic rate to 1/15 of their normal rate.