One of the delights at Malling Down is to sit on a short piece of chalk grassland and wait for the brilliant sky-blue Adonis blue butterfly to come sailing by. Between May and mid-June and again from early August to mid-September you will find the male Adonis blue butterfly on short, warm slopes. The females are brown and far less conspicuous than the males but they can both be identified by the distinctive black lines that cross the white found on the fringes of their wings.
This specialist of chalk grassland has an unusual life cycle. Eggs are laid almost exclusively on horse-shoe vetch. The green larvae are looked after by ants which are attracted by the honey- like secretions expelled from its glands. The ants will protect the larvae from predators often burying it at night. This unusual symbiotic relationship is something seen with other blue butterflies as well.