Dragonflies (order Odonata) are divided into two distinct sub-orders, the Zygoptera or Damselflies and the Anisoptera or Dragonflies. Dragonflies are most easily distinguished from damselflies by seeing them at rest; dragonflies hold their wings horizontally while damselflies hold them close to the body. Dragonflies also have larger eyes, a more powerful flight and shaped forewings and hindwings whilst damselflies have similar shaped wings. There are 25 dragonflies and 17 damselflies currently resident and breeding in Britain. The total number of species recorded is 56 but some of these have not been seen since the 19th Century whilst others are migrants from the continent.

On this menu Dragonflies are shown with a red background, Damselflies with a dark yellow.