Did you know there are approximately 340 different kinds of hummingbirds, some as light as a penny? These champion acrobats of the sky can beat their wings more than 40 times a second, fly backward and even hover in midair, like helicopters. Since it's much easier to hear hummingbird wings than see them, just follow the hum to find the birds.
About the series: Each book in the Welcome to the World of Series introduces children to wildlife through color photographs, lively description and amazing facts.