In the entry American Snout on Wikipedia, they say:
Snout butterflies have prominent elongated mouthparts (labial palpi) which, in concert with the antennae, give the appearance of the petiole (stem) of a dead leaf. Snouts often take advantage of this superb camouflage by hanging upside down under a twig, making them nearly invisible. Wings are patterned black-brown with white and orange markings. The forewings have a distinctive squared off, hook-like (falcate) tip.
In the entry American Snout, the Missouri Department of Conservation said:
Habitat and Conservation. Woods, woodland edges, and suburban yards. Snouts sometimes form local colonies in the vicinity of hackberry trees, with the adults resting on the leaves and visiting nearby flowers.
In the entry American Snout, the University of Florida writes:
The larval hosts of the American snout are hackberry trees (Celtis spp.) in the family Celtidaceae. The two most common hackberries in the eastern U.S. are the more northern hackberry, Celtis occidentalis Linnaeus, and the more southern sugarberry, Celtis laevigata Willd., can usually be recognized by the slightly to heavily warty appearance of their trunks.