Meliboeus Hairstreak

Ok, thanks for the info. I will try to make a video of it moving this "tails" and put here.

The only explanation I have in my mind would be the mimicry of the moving antennae, meaning birds are rather attacking the "unimportant" tail thinking that's the head and eyes rather than going directly to the head. This prevent the butterfly from being killed by the first attack. If you look at my link you see how effective this works and note also the perfect symmetry within the butterfly:
http://www.projectnoah.org/spottings/818...

Thanks bayucca. Do you know why it keeps moving the "tails" even when it is immobile?