Do Worms Turn Into Moths or Butterflies? (What About Earthworms?)

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After a quick glance, if you didn’t know better, you could be forgiven for thinking worms and caterpillars were the same.

After all, they are wriggly, small and found in the garden.

This has led many people to ask the question in the title.

The quick answer is no, worms do not turn into a butterfly or moth. But it depends what you are talking about when you are referring to a “worm”.

Many people use the term “worms” in an interchangeable way, for anything that is small and wriggly.

Some caterpillar species even have the word “worm” in their name, just to add to the confusion! For example, the Tomato Hornworm (which is actually a caterpillar)

However, as you will see, worms are completely different animals to caterpillars.

There are lots of ways you can identify whether an animal you are looking at is a caterpillar or a worm.

As worms and caterpillars are different animals, and caterpillars turn into moths and butterflies, it’s reasonable to conclude that no worms do not also turn into butterflies and moths.

In the following post, we are going to discuss this subject in greater detail and really correct the misconceptions surrounding these different animals.

First, answers to some frequently asked questions.

Does a Worm Turn Into a Moth?

No, a worm does not turn into a moth. A worm is a worm until it dies. Caterpillars are the only animals that turn into moths.

What Kind of Worms Turn Into Moths?

No kind of worms turns into moths, only caterpillars.

Do Green Worms Turn Into Moths?

Green worms do not turn into moths if indeed, you actually mean worms.

However, many caterpillars are green (like the Hornworm) and as some people wrongly assume that they are all one and the same thing, you could be mistaken for thinking those green worms turn into moths.

Do Worms Turn Into Butterflies?

Again, the answer to this question, even when it refers to butterflies is no, worms do not turn into butterflies.

Only caterpillars turn into butterflies.

To help clear up the misidentification problems, we are going to discuss the differences between worms and caterpillars.

moths that turn into butterflies

How to Identify Caterpillars

Caterpillars, rather than being a type of worm, are moths and butterflies in their larval stage.

The best way to tell them apart from the larvae of other insects by taking a closer look at their bodies.

Caterpillars have three pairs of what is often referred to as “true” legs that extend from each segment of their thorax.

On the first two segments of their legs, they don’t have “prolegs”.

Prolegs are the fleshy, little parts that look like legs that are on the other segments.

Depending on the species, caterpillars can have up to eight pairs of prolegs.

Although caterpillars have true heads and mouthparts they can use to chew food, once they leave their chrysalis or pupae as either moths or butterflies, they no longer have those mouthparts.

In their place, they have their proboscis.

The proboscis is an appendage that resembles a tube that allows moths and butterflies to sip nectar from flowers.

As you will see from the following section, they are very different from worms.

How to Identify Worms

It’s important to note before we go any further that while there are many different types and species of worms, they all share similar characteristics and bodies:

  • Worms are not the larval stage of an insect. Caterpillars usually are.
  • Worms start as worms and remains worms for their entire life cycle until they die.
  • In fact, worms are not even classified as insects but are actually a different type of invertebrate.
  • Worms do not have true eyes, arms or even legs.
  • They are able to sense and detect light using their light receptor cells, but they are not eyes.
  • Compared to caterpillars that are quite happy to roam around overground, worms are less comfortable, especially earthworms, in bright environments.
  • They would rather slither around underground.
  • On the subject of them slithering, as they do not have arms or legs, they use muscles on their body to move.
  • Worms do not have as complex bodies as caterpillars.
  • In particular, they do not have the benefit of the mouths and mouthparts that caterpillars have for eating.
  • Though there are some species that have little jaw-like features and small teeth, most worms suck their food into their mouth-like opening when they eat, and grip at it using special muscles.


In short, a worm does not turn into a butterfly or a moth but the confusion is understandable when certain caterpillar species have “worm” in their name.

There are some fairly obvious differences that we’ve mentioned to identify the two which should help if you get stuck or become confused when confronted by a caterpillar.