This large family consists of small, often very colourful or iridescent butterflies, many of them rare. They have three sets of functional legs, but the first pair is smaller in most of the males. The antennae and eyes are usually ringed with white.
The Lycaenidae can be divided into four subfamilies:
1. Blues (subfamily Polyommatinae) owe their name to the colour of the upper surface of their wings. The females are often darker than the males.
2. Coppers (subfamily Lycaeninae) are orange or brown, with dark markings.
3. Hairstreaks and elfins (subfamily Theclinae) are recognizable by the two or three small tails on their hindwings. Often grey or brown, they have colourful markings on the underside of their wings.
4. Harvesters (subfamily Melitaeinae) are distinguished from other Lycaenidae by their special wing veins.