Dragonflies are large predator insects with a long hind body (abdomen) and large composite eyes. They are excellent fliers. A dragonfly fly makes a rustling sound when in flight. The densely veined wings are sturdy, the back wings being broader than the front wings. Large dragonflies can easily cross over to the Wadden Sea and are sometimes seen on the islands in massive numbers. The larvae live in fresh water. They are true predators, just like their parents. They eat mainly aquatic insects. Some species can live for years in water as larva. Adults don't live more than several months. Damselflies resemble dragonflies but are thinner with four equal wings. They are not such good flyers.