The family comprises seven subfamilies, including the blues (Polyommatinae), the coppers (Lycaeninae), the hairstreaks (Theclinae), and the harvesters (Miletinae).

[3][4] Adult individuals often have hairy antenna-like tails complete with black and white annulated (ringed) appearance.

Many species also have a spot at the base of the tail and some turn around upon landing to confuse potential predators from recognizing the true head orientation.

[5] Lycaenid caterpillars are diverse in their food habits and apart from phytophagy, some are entomophagous, feeding on aphids, scale insects, and ant larvae.

Just before the adults emerge, the wings of the butterfly inside the pupal case detach from it, and the pupa becomes silvery.

Several evolutionary adaptations enable these associations, including small glands on the skin of the caterpillars called "pore cupola organs".