Spicebush swallowtail caterpillar

A spicebush swallowtail caterpillar on a stem in Hillsborough, North Carolina. The black "eyes" are not eyes at all but markings on the body behind the true head, which sits small and hidden underneath. Together with the swollen green front, they give a songbird the impression of a little green snake staring back. If the bluff is tested, the caterpillar pushes out a forked, foul-smelling organ called an osmeterium that looks like a flicking snake tongue. It is the easiest mimic in this gallery for many Americans to find: check folded spicebush and sassafras leaves in late summer across the eastern United States.