Dragonflies are often called birdwatchers' insects. They are large, brightly coloured, active in the daytime, and with complex and interesting behavior. Like butterflies, they appeal even to people who don't think highly of insects in general. They have been with us since the dinosaurs lived, and they continue to flourish. Their ancestors were the biggest insects ever, and they still impress us with their size - the largest is bigger than a small hummingbird. There are over 6,000 species of Odonata known at present, and you need only to visit any wetland on a warm summer day to be enthralled by their bright colors and fascinating behavior.