Watching a hummingbird can be mesmerizing. With wings that beat more than 50 times per second, hummingbirds sometimes zoom by so fast that you only hear an insect-like buzzing sound. Hummingbirds can fly at speeds exceeding 25 miles per hour, changing direction instantaneously before coming to a midair stop to hover over a flower.  Hummingbirds, unlike any other birds, can even fly backwards and upside down because they move their wings in a figure-8 shape rather than simply up and down like other birds.