These are small, stocky ants less than 3.5 mm (0.14 in) long, and A. exsanguis is not easy to distinguish from related species.

The dorsal surface is rather more densely covered in short hairs than is the case with Acropyga keira, another species found at La Selva.

[3] This neotropical ant is known from Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Colombia, Venezuela and Argentina.

It lives in colonies underground and this subterranean existence means it is poorly represented in ant surveys; it has been found most often by sifting through leaf litter, but has occasionally been observed under stones or visiting bait.

The fact that it is much more common than might be expected from survey results is shown by the vast swarms of males that were seen twice in 1991 at La Selva Biological Station during the wet season.