The Common Blue butterfly has a wingspan of 1.5 centimetres. The male's blue wings feature a row of yellow spots along the edges and multiple black-centered white spots. The females are brown above with red dots. Different species of blue vary in appearance.
The Common Blue lives in grassy areas and at the edge of woodlands and clearings. It can be found throughout Europe, North Africa and Asia.
The butterfly flies at moderate speeds and heights. It feeds on herbaceous plants and flowers. Males congregate in large numbers on moist soil. Eggs are laid singly on the shoots of herbaceous plants. The Common Blue hibernates as a pale-green caterpillar at the base of a plant or on the forest floor.