Common Caerulean

Description:

'The pattern of white striations diverts the eyes of avian predators away from the real head, and towards the orange-rimmed back ocellus and "false-antennae" tails. Attacking birds aim their beaks towards the area in which they predict a butterfly will try to make it's escape, i.e. in front of the head. The markings on the wings fool them into aiming just behind the butterfly instead, and the insect makes it's escape in the opposite direction.

Habitat:

tropical rainforest

Notes:

I spotted this in Bukit Timah nature reserve.