Caterpillars and worms do not live “together” in their immediate habitats, but they do co-exist quite well in the same areas. Let us explain. Worms dig tunnels in the soil where they can feed and hide from elements such as the hot sun. Caterpillars, on the other hand, prefer areas that have plenty of sunshine. If a worm remains in the sun for too long, the skin, which must stay moist at all times, will dry out. If the skin dries out, the worm can die from suffocation. The sun can also cause the worm to become paralyzed. Worms have no lungs, so they breathe through their skin. This means that the worm’s environment and skin must be moist at all times. This allows the worm to breathe in oxygen.

While worms need moisture to survive, too much moisture can be fatal. If too much water is present, it takes the place of oxygen, which will cause the worms to flee to the surface. Caterpillars can tolerate the sun just fine, but the wind is altogether different story. The wind can easily blow the caterpillar in a direction it does not want to go as it transforms into a butterfly.

Earthworms typically live in the upper areas of soil, which offers the moist environment it needs to survive and easy access to food sources. Some also live deep within the earths soil. Earthworms eat all types of organic matter such as leaves and dead grass, which contain organisms that provide a healthy diet of bacteria, algae, and fungi. Worms feast on dirt as well, especially if they live deeper inside the earth. Worms also eat plants, fruits, and vegetables.

Caterpillars eat a wide variety of plants, flowers, and fruits. It just depends on the type of caterpillar the host it prefers. For example, some caterpillars such as the larvae of the eastern tiger swallowtail, prefer wild cherry, basswood, birch, ash, mountain ash, and willow, while the larvae of the white admiral prefers
birch, aspen, poplar, willow, hawthorn, basswood, and amelanchier.

Other Differences between Caterpillars and Worms

One of the most obvious differences between caterpillars and worms is caterpillars move around on three pairs of legs, while worms have no limbs at all. Worms move around by contracting their segments. Each segment has two pairs of hairs called setae. The setae help worms grip the soil or other materials. In general, worms and caterpillars move slowly. When faced by an attacker, however, they can move fairly quickly.

Caterpillars are often described as “wormlike” creatures, but worms and caterpillars have just as many differences as they have similarities. Two of the most obvious similarities between worms and caterpillars are: both worms and caterpillars have soft bodies, meaning they do not have a skeletal system, and both animals are nocturnal. Depending on the species worm, some caterpillars and worms may also be similar in length. Some caterpillars may grow up to three inches or more.

There are literally thousands of different species of worms and more than 2,700 species of earthworm alone. Like earthworms (annelida), caterpillars have segmented bodies. Another similarity between caterpillars and worms is caterpillars and worms are a favorite food for other animals. They are both protein rich and some worms, such as the white worm or “pasta worm”, are raised specifically for feeding to other animals such as fish. Worms and caterpillars are known for having hearty appetites. Their appetites are so hearty that they have earned the name “pest” by farmers around the globe. Depending on the type of worm or caterpillar, they can eat through crops of all kinds, plants, trash, and even inedible materials such as cotton.

Worms and caterpillars have to defend themselves against a wide variety of predators quite regularly. Because of this, each animal has no choice but to utilize a wide variety of techniques to ward off attacks. Worms protect themselves in several ways. If their attackers hunt for them below ground, worms will quickly withdraw into their burrows. If a worm finds itself face to face with a predator on the surface, the worm will thrash about, jump, and twist their bodies. Some worms may also spit and spew a foul smelling or foul tasting fluid.

The caterpillar is just as aggressive when it comes to defending itself. Caterpillars have long hairs or bristles on their bodies, which can detach and lodge into the skin or mucous membranes of the predator. In some caterpillars, the bristles contain poison from the caterpillar’s venom glands. This poison is so powerful that in the case of the South American silk moth, it can be fatal to human beings. Much like worms, caterpillars also spit juices and produce bad smells to ward off attackers. Caterpillars also have the ability to create a silk line and drop out of site if a predator approaches. How amazing is that?

Sources

The University of Maine Cooperative Extension Publications “Landscaping for Butterflies in Maine.” http://umaine.edu/publications/7151e/