What was the looming mass of entomological detritus? Here’s the culprit:
As Gabriela- who we had the great pleasure to meet during our travels- so aptly guessed, the mystery mound was a nest of Camponotus rufipes. Here’s a clearer shot of the same nest, taken on the campus of the Universidade Federal de Viçosa:
Incidentally, the Brazilian pronunciation of “rufipes” (“HOOF-ih-pees”) made me giggle every time I heard it, as though the soft R took the edge off one of the continent’s most aggressive insects.