They are laid either singly or in groups of up to four on the upper surface of the host plant leaves, favoring nut trees such as Juglans and Carya (walnuts and hickories).

The caterpillars are solitary nighttime feeders in early stages, when they curl up in a "j" shaped pattern during the day and resemble two-toned bird droppings.

Their frightening appearance is purely a ruse; the spines, though prickly, do not sting, and the larva is harmless and actually one of the more easily handled of the saturniidae.

Just before pupation, the larva expels its gut and changes color from green to turquoise, the skin of the fully fed creature stretched shiny and tight.

Some pupae overwinter for two seasons, perhaps as an adaptation to variable and adverse conditions such as fires and flooding, or to maintain genetic diversity across generations.

There is a single generation of Citheronia regalis throughout its range, but in the deep south, moths have been recorded throughout the longer growing season.

It is found throughout the deciduous forests in the United States from Missouri, Pennsylvania to Massachusetts and southward from Texas to central Florida.