Fluttering by

Having got rather cold wandering round the park we decided to visit the butterfly house.

I've done a bit of Googling and have identified this as a Glasswing butterfly. Aptly named, its wings are quite transparent as it does not have the colour giving scales of other butterflies and moths. The advantage of this is that it makes it hard to follow as it flits about.

An Owl butterfly; as well as the eye spots, this also seems to have snake mimicry. How did this all evolve?