The Spicebush Swallowtail butterfly (Papilio troilus) goes through 6 instars, or stages, of development before pupating. In the 4th instar this caterpillar is brown with white splotches, resembling bird droppings. The 5th instar brings a dramatic change to this colorful, almost comic, look. The large false eye spots help make the caterpillar look like a small snake, which helps keep away its main predator - birds. Canon 100mm lens, ISO 100, F/9, 1/200 second.