STALK EYE FLY (fly family Diopsidae) ©log-in08
These small but spectacular creatures are mostly found in the jungles of South East Asia and Africa, with a few species also found in Europe and North America. They get their name from the long projections from the sides of the head with the eyes and antennae at the end. Male flies usually have much longer stalks than females and it has been confirmed that females prefer males with long eyestalks. Males during mating season often stand face to face and measure their eyestalk’s length; the one with the greatest “eye span” is recognized as the winner.
Male stalk eyed flies also have the extraordinary ability to enlarge their eyestalks by ingesting air through their mouth and pumping it through ducts in the head to the eyestalks. They do this mostly during mating season. Here’s an amazing video of the male stalk eyed fly, newly emerged from its cocoon, actively enlarging his eyestalks: