Owl butterflies earned their name from their eyespots, which resemble the wide open eyes of owls. With drab brown coloring, owl butterflies blend in to the tree trunks where they rest.
Caligo idomeneus lives in most of the Amazon region east of the Andes, from Venezuela and Ecuador south to Brazil.
Adult butterflies nectar primarily on rotting fruit on the forest floor. Larvae feed on leaves of heliconia, a genus that includes lobster-claw, wild plantain and false bird-of-paradise.