Hummingbirds are small birds that belong to the family Trochilidae. The name ‘Hummingbird’ is derived from the characteristic ‘hum’ made a hummingbird’s rapid wing beats. Most species of hummingbird have an average length of 7.5–13 cm. Hummingbirds are the only group of birds that can fly backwards. They can hover in mid-air by rapidly flapping their wings 12–90 times per second (depending on the species).
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