# Fact check - number of ants related

**URL:** <https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008>\
**Category:** Factual Questions\
**Created:** [September 8, 2018, 4:42pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008 "2018-09-08T16:42:32Z")\
**Posts on this page:** 19\
**Page:** 1

<div class="post-metadata">

**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\
**Post date:** [September 8, 2018, 4:42pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/1 "2018-09-08T16:42:32Z")

</div>

I was reading Quora and an answer to one question states that if all the ants on earth were laid end to end they could circle “about five times the diameter of the entire solar system!”

That’s seems implausible. What say the TMs?

---

<div class="post-metadata">

**Author:** ![Kamino\_Neko](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kamino_neko/32/34_2.png) [@Kamino\_Neko](https://boards.straightdope.com/u/Kamino_Neko)\
**Post date:** [September 8, 2018, 5:19pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/2 "2018-09-08T17:19:26Z")

</div>

Doing some quick checks…

Estimated diameter of the solar system 4.545 billion km (or 4.545 quadrillion cm, for ease of later comparisons).  
Estimated number of ants on Earth - 10 quadrillion.

Average length of an ant… I cannot find any hard numbers. A quick look through various species and casts within them…I’d guess about 1cm is a safe estimate. (Anyone who knows better, please correct me.)

So, the length of all ants laid mandibles to abdomen would be about 10 quadrillion cm. So…assuming I haven’t done a conversion wrong\*…‘only’ a bit more than twice the diameter of the solar system…which is still pretty impressive.

- My checks are saying I’m good, but if I’m brain-farting at a fundamental level, not just messing up numbers, I could be repeating the same mistake repeatedly.

---

<div class="post-metadata">

**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\
**Post date:** [September 8, 2018, 6:20pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/3 "2018-09-08T18:20:52Z")

</div>

The answer depends on what diameter you assign to the solar system. There’s several possibilities:

1. Just the planets, so use the semi-major axis of Neptune (30 AU)
2. The “old” solar system, i.e. considering Pluto as the edge (39.5 AU)
3. The outer edge of the classic Kuiper Belt (50 AU)
4. The furthest distance that a known object (except comets) gets (936 AU)
5. Planet nine (we don’t know where that is, so we can’t give a number but likely somewhere between 500 and 1000 AU)
6. the Oort Cloud (1 lightyear or more)

---

<div class="post-metadata">

**Author:** ![Wendell\_Wagner](https://avatars.discourse-cdn.com/v4/letter/w/8491ac/32.png) [@Wendell\_Wagner](https://boards.straightdope.com/u/Wendell_Wagner)\
**Post date:** [September 8, 2018, 6:25pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/4 "2018-09-08T18:25:53Z")

</div>

There are 100,000 centimeters in a kilometer, not 1,000,000. So the diameter is 454.5 trillion centimeters. An average ant is .7 centimeters. There are 10 quadrillion ants in the world. So they have a total length of 7 quadrillion centimeters, which is about 15 times the length of the diameter.

What does it mean to say that they would circle about five times the diameter of the solar system? A diameter is not a circle. That’s a circumference. The circumference of the solar system is about 2.856 quadrillion centimeters. The ants would circle the solar system more than two and a half times.

---

<div class="post-metadata">

**Author:** ![Kimble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kimble/32/19185_2.png) [@Kimble](https://boards.straightdope.com/u/Kimble)\
**Post date:** [September 8, 2018, 6:26pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/5 "2018-09-08T18:26:35Z")

</div>

> [@Kamino\_Neko](#):
>
> Doing some quick checks…
> 
> Estimated diameter of the solar system 4.545 billion km (or 4.545 quadrillion cm, for ease of later comparisons).

1. That’s the radius of Neptune’s orbit, not the diameter.
2. Your conversion from kilo- to centi- is off – 1 km = 100,000 cm = 1,000,000 mm.

So, the diameter should be 0.9090 quadrillion cm.

> [@](#):
>
> Estimated number of ants on Earth - 10 quadrillion.
> 
> Average length of an ant… I cannot find any hard numbers. A quick look through various species and casts within them…I’d guess about 1cm is a safe estimate. (Anyone who knows better, please correct me.)
> 
> So, the length of all ants laid mandibles to abdomen would be about 10 quadrillion cm. So…assuming I haven’t done a conversion wrong\*…‘only’ a bit more than twice the diameter of the solar system…which is still pretty impressive.
> 
> - My checks are saying I’m good, but if I’m brain-farting at a fundamental level, not just messing up numbers, I could be repeating the same mistake repeatedly.

10 / 0.909 is about 11, but if ants are more like 4.5 mm (which is plausible, but I don’t know), Quora would be accurate.

[Edit on preview: what **dtilque** said, but I think Neptune’s aphelion is another reasonable [Edit #2: radius, with its implied diameter] to use.]  
[Edit on post: ninjaed by **Wendell Wagner**]

---

<div class="post-metadata">

**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\
**Post date:** [September 8, 2018, 6:34pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/6 "2018-09-08T18:34:42Z")

</div>

> [@dtilque](#):
>
> The answer depends on what diameter you assign to the solar system.

Oops, I meant radius.

> [@](#):
>
> 1. The furthest distance that a known object (except comets) gets (936 AU)

And this is somewhere around 8100 AU (plus or minus a bunch).

Re: Neptune’s aphelion: that planet has a very circular orbit, so 30 AU works for either perihelion or aphelion. Pluto, on the other hand has a very non-circular orbit. I gave the semi-major axis for that.

---

<div class="post-metadata">

**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\
**Post date:** [September 8, 2018, 6:37pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/7 "2018-09-08T18:37:44Z")

</div>

I’m not sure how you would even calculate the average length of an ant, since you would not only have to know the average length for each species (and many species are made up of various castes that vary enormously in length), as well as the number of ants in each species (and between species colonies can consist of a few dozen workers into the millions).

This said, the estimate of 1 cm seems high to me, since many ant species, and possibly the most numerous ones, are quite small. Something like 4.5 mm might be more like it.

At any rate, the calculations given here suggest that the figures are within the right order of magnitude, at least.

---

<div class="post-metadata">

**Author:** ![Wendell\_Wagner](https://avatars.discourse-cdn.com/v4/letter/w/8491ac/32.png) [@Wendell\_Wagner](https://boards.straightdope.com/u/Wendell_Wagner)\
**Post date:** [September 8, 2018, 6:40pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/8 "2018-09-08T18:40:53Z")

</div>

I screwed it up too. Insert the word “radius” wherever I wrote “diameter”. I think the final calculations are correct though.

---

<div class="post-metadata">

**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\
**Post date:** [September 8, 2018, 6:45pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/9 "2018-09-08T18:45:47Z")

</div>

> [@dtilque](#):
>
> Re: Neptune’s aphelion: that planet has a very circular orbit, so 30 AU works for either perihelion or aphelion. Pluto, on the other hand has a very non-circular orbit. I gave the semi-major axis for that.

Does it make a difference if they orbit clockwise or antyclockwise?

---

<div class="post-metadata">

**Author:** ![Kamino\_Neko](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kamino_neko/32/34_2.png) [@Kamino\_Neko](https://boards.straightdope.com/u/Kamino_Neko)\
**Post date:** [September 8, 2018, 6:46pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/10 "2018-09-08T18:46:37Z")

</div>

> [@Wendell\_Wagner](#):
>
> There are 100,000 centimeters in a kilometer, not 1,000,000.

Oops…yep, that is definitely a fundamental brainfart.

And I should have doublechecked the radius/diameter thing, but that seemed to be the most solid number I was likely to get, and didn’t bother.:smack:

---

<div class="post-metadata">

**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\
**Post date:** [September 8, 2018, 7:10pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/11 "2018-09-08T19:10:08Z")

</div>

> [@Lucas\_Jackson](#):
>
> I was reading Quora and an answer to one question states that if all the ants on earth were laid end to end

Too bad Dorothy Parker isn’t around to provide a snappy answer.

---

<div class="post-metadata">

**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\
**Post date:** [September 8, 2018, 7:32pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/12 "2018-09-08T19:32:01Z")

</div>

> [@Jackmannii](#):
>
> Too bad Dorothy Parker isn’t around to provide a snappy answer.

It doesn’t help that most of them are sterile females.

---

<div class="post-metadata">

**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\
**Post date:** [September 8, 2018, 8:12pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/13 "2018-09-08T20:12:47Z")

</div>

> [@Riemann](#):
>
> Does it make a difference if they orbit clockwise or antyclockwise?

Groan…

🙂

---

<div class="post-metadata">

**Author:** ![Nansbread1](https://avatars.discourse-cdn.com/v4/letter/n/6a8cbe/32.png) [@Nansbread1](https://boards.straightdope.com/u/Nansbread1)\
**Post date:** [September 8, 2018, 8:36pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/14 "2018-09-08T20:36:35Z")

</div>

Replace ants with E Coli and i presume the results will be spectacular too.

---

<div class="post-metadata">

**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\
**Post date:** [September 8, 2018, 8:45pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/15 "2018-09-08T20:45:21Z")

</div>

Yes, part of the issue here is just simple dimensionality. If you take a 3-dimensional volume of anything made up of small pieces and lay the pieces end to end you are likely to get something counterintuitively long.

I wonder if the biomass of ants vs (say) humans is similarly impressive?

ETA: to answer my own question - no, similar or less than humans.  
Per this article, earthworms appear to be the biomass kings.

> **[Biomass (ecology)](https://en.wikipedia.org/wiki/Biomass_(ecology))**
>
> The biomass is the mass of living biological organisms in a given area or ecosystem at a given time. Biomass can refer to species biomass, which is the mass of one or more species, or to community biomass, which is the mass of all species in the community. It can include microorganisms, plants or animals. The mass can be expressed as the average mass per unit area, or as the total mass in the community.
> How biomass is measured depends on why it is being measured. Sometimes, the biomass is reg...

---

<div class="post-metadata">

**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\
**Post date:** [September 8, 2018, 8:50pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/16 "2018-09-08T20:50:58Z")

</div>

correct url  
[https://en.wikipedia.org/wiki/Biomass\_(ecology)#Global\_biomass](https://en.wikipedia.org/wiki/Biomass_(ecology)#Global_biomass)  
see rightmost column in table

---

<div class="post-metadata">

**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\
**Post date:** [September 8, 2018, 9:33pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/17 "2018-09-08T21:33:48Z")

</div>

Another solar system [comparison](https://www.sciencefocus.com/the-human-body/how-long-is-your-dna/): “… all the DNA in all your cells put together would be about twice the diameter of the Solar System.”

So, the real question is if you took the DNA from those ants and put it end-to-end … who would clean up all that mess?

---

<div class="post-metadata">

**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\
**Post date:** [September 8, 2018, 9:39pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/18 "2018-09-08T21:39:34Z")

</div>

> [@ftg](#):
>
> Another solar system [comparison](https://www.sciencefocus.com/the-human-body/how-long-is-your-dna/): “… all the DNA in all your cells put together would be about twice the diameter of the Solar System.”
> 
> So, the real question is if you took the DNA from those ants and put it end-to-end … who would clean up all that mess?

DNA is really impressive, because the dimensionality thing does not apply: each chromosome is a continuous linear structure within the cell. The figure often cited is that all the DNA in a human cell is about 2m long if stretched out. So it requires sophisticated molecular machinery to pack it all up so it fits, but then to unpack it as necessary for transcription, replication, meiosis…

---

<div class="post-metadata">

**Author:** ![wolfman](https://avatars.discourse-cdn.com/v4/letter/w/a8b319/32.png) [@wolfman](https://boards.straightdope.com/u/wolfman)\
**Post date:** [September 8, 2018, 9:59pm UTC](https://boards.straightdope.com/t/fact-check-number-of-ants-related/821008/19 "2018-09-08T21:59:04Z")

</div>

> [@Riemann](#):
>
> correct url  
> [https://en.wikipedia.org/wiki/Biomass\_(ecology)#Global\_biomass](https://en.wikipedia.org/wiki/Biomass_(ecology)#Global_biomass)  
> see rightmost column in table

So if there are 1 x 10[sup]31[/sup] Prokaryotes, and the average size were 1µm(just picking a feasible and easy to work with number, not saying it is the true average size), there would be a 1 x 10[sup]25[/sup] meter (10 ym line of them).
