Have you ever seen a caterpillar with eyes? Not just any eyes, but big, round, yellow eyes that stare back at you. If you have, you might have encountered a spicebush swallowtail caterpillar, one of the most amazing examples of mimicry in nature.
The spicebush swallowtail caterpillar (Papilio troilus) is a larva of a black and blue butterfly that belongs to the family Papilionidae. It is native to eastern North America and feeds on the leaves of spicebush (Lindera benzoin) and sassafras (Sassafras albidum) plants.
But what makes this caterpillar so special is its ability to change its appearance depending on its stage of development and the level of threat it faces. When it is young and small, it looks like a bird dropping, which helps it blend in with the foliage and avoid being eaten by birds. As it grows older and larger, it develops two pairs of false eyespots on its thorax, which resemble the eyes of a snake. When disturbed, it can inflate these eyespots and stick out a forked tongue-like organ called an osmeterium, which emits a foul-smelling substance. This way, it can scare off potential predators such as birds, lizards, and rodents.
The spicebush swallowtail caterpillar is not the only insect that uses mimicry to survive. There are many other examples of insects that look like other animals or plants to fool their enemies or prey. For instance, some moths have markings that resemble owl eyes or wasp stripes. Some butterflies have wing patterns that resemble dead leaves or flowers. Some beetles have shapes and colors that mimic ants or ladybugs.