Formlings, now better understood to depict termitaria (termites' nests) and termites, are a pervasive category of San (Bushman) rock art north of the River Limpopo. This article investigates the associations of termites' nests in San thought, belief, and ritual, in an attempt to explain formling symbolism and why termites' nests, and not other subjects, were chosen for depiction. Unequivocal ethnographic testimonies of San spiritual world-view are compounded with iconographic analysis to show nuances of San understanding and perception of the spirit world. In turn, this ethnographic hermeneutic reveals a significant but previously unexplored facet of spirit-world imagery which evokes notions of creative and transformative power. This newly highlighted vignette of San cosmology unlocks aspects of San imagery, such as the interface between the natural and the metaphysical, that have hitherto been less understood.