# Earthworms-animal or insect

**URL:** <https://boards.straightdope.com/t/earthworms-animal-or-insect/67135>\
**Category:** Factual Questions\
**Created:** [May 31, 2001, 10:24pm UTC](https://boards.straightdope.com/t/earthworms-animal-or-insect/67135 "2001-05-31T22:24:04Z")\
**Posts on this page:** 11\
**Page:** 1

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**Author:** ![mothman](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@mothman](https://boards.straightdope.com/u/mothman)\
**Post date:** [May 31, 2001, 10:24pm UTC](https://boards.straightdope.com/t/earthworms-animal-or-insect/67135/1 "2001-05-31T22:24:04Z")

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Why are worms considered to be an insect and not as an animal? They (worms) have a heart, brain, and central nervous system so shouldnt they be in the animal kingdom? Also are they warm-blooded or cold?  
How do scientists classify animals or insects? What is the criteria?

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**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\
**Post date:** [May 31, 2001, 10:31pm UTC](https://boards.straightdope.com/t/earthworms-animal-or-insect/67135/2 "2001-05-31T22:31:35Z")

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Mothman you’re way off here. Earthworms are NOT considered Insects, and Insects ARE considered animals. Where are you getting your misinformation from? They are invertebrates… and therefore cold blooded.

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**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\
**Post date:** [May 31, 2001, 10:56pm UTC](https://boards.straightdope.com/t/earthworms-animal-or-insect/67135/3 "2001-05-31T22:56:39Z")

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**mothman:** - you sure you don’t mean _invertebrate_?

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**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\
**Post date:** [May 31, 2001, 11:04pm UTC](https://boards.straightdope.com/t/earthworms-animal-or-insect/67135/4 "2001-05-31T23:04:44Z")

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Doesn’t matter… both insects and earthworms are invertebrates and neither have backbones(vertebra). Insects have exoskeletons…

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**Author:** ![Shiva](https://avatars.discourse-cdn.com/v4/letter/s/85e7bf/32.png) [@Shiva](https://boards.straightdope.com/u/Shiva)\
**Post date:** [May 31, 2001, 11:42pm UTC](https://boards.straightdope.com/t/earthworms-animal-or-insect/67135/5 "2001-05-31T23:42:12Z")

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From: [http://res2.agr.ca/london/pmrc/english/faq/earthwor.html](http://res2.agr.ca/london/pmrc/english/faq/earthwor.html)

> [@](#):
>
> The following is a classification of a species in the earthworm family Lumbricidae. This common species is Lumbricus terrestris also known as the night crawler or dew worm.
> 
> ```auto
> 
> Phylum - Annelida
> Class - Clitellata
> Subclass - Oligochaeta
> Order - Haplotaxida
> Suborder - Lumbricina
> Superfamily - Lumbricoidea
> Family - Lumbricidae
> Genus - Lumbricus
> Species - terrestris
> 
> ```

The Phyla Annelida and Insecta are both included in the Kingdom Animalia, so worms and insects are both animals in the technical sense.

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**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\
**Post date:** [June 1, 2001, 12:20am UTC](https://boards.straightdope.com/t/earthworms-animal-or-insect/67135/6 "2001-06-01T00:20:41Z")

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If you’re asking why worms aren’t considered insects (it’s possible!), well, worms don’t have 6 legs, they don’t have any wings, they have more than three body segments, they don’t have exoskeletons, etc, etc, etc.

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**Author:** ![JRDelirious](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jrdelirious/32/9531_2.png) [@JRDelirious](https://boards.straightdope.com/u/JRDelirious)\
**Post date:** [June 1, 2001, 1:35am UTC](https://boards.straightdope.com/t/earthworms-animal-or-insect/67135/7 "2001-06-01T01:35:36Z")

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The question makes no sense as it is. Earthworms are animals, insects are a different kind of animal (that, BTW, also have digestive, circulatory and central nervous systems). What we need is clarification of what _did_ **mothman** mistakenly believe “insect” and “animal” to mean.

jrd

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**Author:** ![Phobos](https://avatars.discourse-cdn.com/v4/letter/p/3d9bf3/32.png) [@Phobos](https://boards.straightdope.com/u/Phobos)\
**Post date:** [June 1, 2001, 1:23pm UTC](https://boards.straightdope.com/t/earthworms-animal-or-insect/67135/8 "2001-06-01T13:23:21Z")

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The [Tree of Life](http://phylogeny.arizona.edu/tree/life.html).

Here, you can see that insects and worms [are both animals](http://phylogeny.arizona.edu/tree/eukaryotes/animals/animals.html). They’re just different kinds of animals.

If I can generalize & personify here for a moment…  
If you’re alive, then you’re either an animal, a plant, a fungi, or a bacteria.  
If you’re a virus, then you’re not sure whether you are alive or not.

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**Author:** ![Tamerlane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tamerlane/32/7602_2.png) [@Tamerlane](https://boards.straightdope.com/u/Tamerlane)\
**Post date:** [June 1, 2001, 3:10pm UTC](https://boards.straightdope.com/t/earthworms-animal-or-insect/67135/9 "2001-06-01T15:10:27Z")

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**Phobos** : Actually I’d add one. The five “classic” Kingdoms still taught in most basic biology courses are:  
Monera - Bacteria  
Protista - Protozoa  
Plantae - Plants  
Fungae - Fungi  
Animalia - Animals

Of course some people divide critters up into a couple dozen different Kingdoms these days, but the above is good enough for government work. Especially given the lack of consensus.

- Tamerlane

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**Author:** ![mothman](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@mothman](https://boards.straightdope.com/u/mothman)\
**Post date:** [June 1, 2001, 4:51pm UTC](https://boards.straightdope.com/t/earthworms-animal-or-insect/67135/10 "2001-06-01T16:51:29Z")

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Well now I see my mistake. I was under the impression worms WERE insects like millipedes and centipedes. I had no idea that you had to have legs to be considered an insect and not something else. Either way worms to me will always be considered a “bug”

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**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\
**Post date:** [June 1, 2001, 5:12pm UTC](https://boards.straightdope.com/t/earthworms-animal-or-insect/67135/11 "2001-06-01T17:12:41Z")

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In one of Richard Dawkins’ books he mentions a court case that involved a cruelty to animals suit brought by somebody concerned about resturaunts boiling lobsters live. The court ruling was that cruelty to animals laws did not apply because lobsters were “insects, not animals”.

It seems that to much of the general public, “insect” is a catch-all term used for any living thing which isn’t clearly something else. And “animal” is a flexible term which may include birds or lizards, but maybe will not include fish or snakes (I have seen both excluded from the term “animal” in the popular press). In extreme circumstances, people seem to think “animal” is a synonym for “mammal”.

And I’ll agree with Tamerlane’s kingdoms. I remember being taught two back in 8th grade, and having arguments about whether a bacteria was a plant or an animal (IIRC, I was told it was a plant - that never did seem right). Of course, as a mildly interested outsider, it seems to me that the trend in modern day taxonomy is to resolve all difficult questions by creating new orders and families (rabbits USED to be rodents, and I had no difficulty with that), while merging a lot organisms at the species level. And yes, I’m aware that there is a “genus” level.
