I recently bought a (wireless) flashgun, a Nissin Di622 mark II for my Sony. And tried the Vivitar 100F3.5 Macro with a method I read from Robin Wong: I used the flashgun hand-held and the camera on the other hand. Firstly. Then I put the camera on a tripod, but with the flash still hand-held, to control lighting.
Click for a bigger version.
(By the way, the photo is upside down. For ants, gravity is a matter of opinions…)