And this is where the story becomes interesting. The butterfly has a symbiotic relationship with a species of ants called Allegheny Mound Builders, Formica exsectoides. These ants build huge mounds that can reach two to three feet in height and four or five feet in width. The ants are always busy collecting food and protecting their mound. I observed many ants carrying dead insect and spiders to the mound. Below is a mound of the Allegheny Mound Builders.
The ants also rely on the caterpillars for a food source. The caterpillars produce a sugary secretion called honeydew. The ants will carry the older caterpillars down into the mounds at the base of the oak trees. The moundbuilders will "milk" the caterpillars of the honeydew and in return protect them while they are feeding in the trees and keep them safe in the mounds. Later, the caterpillars will pupate inside the mounds.