Do Caterpillars and Worms Eat the Same Things?

Depending on the type of worm or caterpillar, these protein rich creatures may eat plants of all kinds. Many are considered pests, so in these cases, the worm or caterpillar will eat everything from trash to cotton. Generally speaking, however, worms and caterpillars – the ones that are not considered pests, prefer to eat foods from the earth, such as leaves, and dead grass. These materials contain organisms that provide a steady diet of bacteria, algae, and fungi. Worms feast on dirt as well—especially if they live deeper inside the earth than the average soil dwelling worm. Worms also eat plants, fruits, and antioxidant rich vegetables. In addition to plants, caterpillars may eat seeds, seed pods, or flowers. Certain caterpillars, such as the caterpillar of the Harvester butterfly may nosh on aphids — a plant-sucking insect.

Worms and caterpillars have strong appetites. Worms eat so much that they typically produce excrement equal to their own weight every 24 hours. Some caterpillars have earned the name “pest” because in high enough numbers they can eat through entire fields of plants and flowers, killing the plants in the process.

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Continue to the next section to learn how to tell the difference between caterpillars and worms.

Is it a Caterpillar or a Worm?

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.

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Caterpillars are often described as “wormlike” creatures, but the two have many similarities and differences. 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?

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