Bagheera kiplingi inhabits Mimosaceae trees, Vachellia in particular, where it consumes specialized protein- and fat-rich nubs called Beltian bodies. The nubs form at the leaf tips of the acacia as part of a symbiotic relationship with certain species of ants. The spiders actively avoid the ants that attempt to guard the Beltian bodies (their food source) against intruders. Although the Beltian bodies account for over 90% of B. kiplingi diet, the spiders also consume nectar and occasionally steal ant larvae from passing worker ants for food. Sometimes, they cannibalize conspecifics, especially during the dry season.

Despite their occasional acts of predation, the spiders' tissues have been found to exhibit isotopic signatures typical of herbivorous animals, implying that most of their food comes from plants.[3][6] The mechanism by which they process, ingest, and metabolize the Beltian bodies is still unresearched. The vast majority of spiders liquefy their prey using digestive enzymes before sucking it in.