The gland is orange red, fleshy, forked and generally intimidating to potential predators. The mimicry induced by the eyespots and forked gland give the caterpillar the appearance of a snake, adding to its defense mechanisms against potential predators. The caterpillar lives in a nest that it creates in the trees by folding a leaf over itself and pulling together the two halves with silk. By the time it is ready to undergo metamorphosis, the caterpillar can grow to be up to 5 cm (2 in) long. About a month is needed for the egg to develop into an adult. Fully-grown caterpillars tend to be green. After hatching, the caterpillar usually eats the egg shell. The caterpillars have been known to eat from the black cherry. The Appalachian tiger swallowtail is univoltine. Female butterflies usually lay their singular brood from May to June. During the mating season, the males fly through the treetops, scouting for females. Females, though, tend to be difficult to find because they prefer to hide in the forest canopy. After mating, females lay their eggs singularly on host plant leaves. The caterpillars, after hatching, then eat the host plants' leaves and undergo chrysalis throughout the winter. Pupation occurs around late June to July and pupae diapause until spring. Adults hatch in May. Appalachian tiger swallowtail butterflies tend to congregate in the woodlands and woodland openings. They prefer to remain in mid-level to high elevations in the southern Appalachian Mountains, and the species' range stretches from Pennsylvania to Georgia and Alabama. This species is extremely prevalent at higher elevations, but can also be found at lower elevations or valleys within mountainous terrain. The adult butterflies tend to remain in the canopy of the Appalachian hardwood forest and mainly only leave when visiting flowers. Their habitats often parallel those of "P. glaucus". Adults drink nectar from many plants, including the mountain laurel ("Kalmia latifolia"), the pink azalea ("Rhododendron nudiflorum"), the blackberry ("Rubus"), the cockspur thorn ("Crataegus crus-galli"), the multiflora rose ("Rosa multiflora"), and the bush honeysuckle ("Diervilla"). Near the summit, they also tend to drink from the autumn olive ("Elaeagnus commutata"), but at lower elevation, they drink from the daisy fleabane ("Erigeron ramosus").