Some flies in this family (Micropezidae) are ant mimics, while others mimic wasps as this one does.
As it made its way from one leaf to the next, it would wave its forelegs and flash those tiny white feet in a very wasp antennae fashion.
There were a number of wasp species in the area with white tipped antennae. This guy fooled the best of them. They had no clue there was an actor in their midst.
And check out those eyes!
Canon 5D Mark II, EF100mm f2.8L macro IS USM, ring flash, ISO 100, 1/60, f9, handheld
December 2016, Costa Rica