Hummingbird ( Trochilidae ) ~ They are the smallest of birds, most species measuring in the 7.5-13 cm range. The 5 cm Bee-Hummingbird, they hover in mid-air by rapidly flapping their wings 12-80 times per.second. They are known as hummingbirds because of the humming sound created by their beating wings, which sometimes sounds like bees or other insects. They are also the only group of birds with the ability to fly backwards.
