Ant Course in Uganda was phenomonal. There’s nothing like having 40 keen sets of eyeballs out searching for ants in an understudied tropical forest for 10 days. Under such intense effort, all sorts of rare material turns up, including species that are almost never seen alive, much less photographed.
This particular oddity I can actually claim to have found on my own, a tiny ant less than 3 millimeters long running around under a rotting log. I brought her back to the lab to photograph so I wouldn’t lose the specimen.
So little is known about this ant that no one even knows what it eats. Bob Taylor (1965) kept a colony once but the ants refused everything he tried to feed them. Yet, Probolomyrmex is widespread in the tropics and occurs in the undercollected deep soil habitat, so it may be one of those animals that ends up being more common once myrmecologists figure out how to look for it.
*update (9/27): Wait! Stop the Presses! Roberto Keller points us to this photograph from Donat Agosti’s 1995 revision of the South American species: