Hummingbirds have become the greatest aerial acrobats on earth. They can hover, fly backwards and even fly backwards and upside down simultaneously. Plants have ?created? hummingbirds as their messengers, carrying pollen from flower to flower. The smallest warm-blooded creatures on the planet, hummingbirds also have the highest metabolism of any vertebrate. The film explores the evolution of the birds, as they are shaped by their role as go-betweens for plants.