
Dogs poop in alignment with Earth’s magnetic field, study finds (2014) - pionerkotik
https://www.pbs.org/newshour/science/dogs-poop-in-alignment-with-earths-magnetic-field-study-finds
======
jwmerrill
This study hinges on binning by variability of the magnetic field. It’s
important to realize how small these variations are. The authors measure
variation in the field direction in “percent”, but the units are arch minutes
(1/60 of a degree in compass heading) per minute of time [0]. Calling this a
percentage is kind of an odd pun on two meanings of the word “minute”.

According to the authors’ own interpretation, variation of 2 arch minutes of
heading per minute of time is enough to destroy the claimed effect. In other
words, they’re talking about a 0.03 degree change in direction in the amount
of time it takes a dog to poop.

Perhaps you believe dogs are sensitive to magnetic fields, but can you really
believe that they are also sensitive to such tiny relative variations in
magnetic fields? Much more sensitive than a handheld compass?

I also agree with the general criticisms about p-hacking, but I think it’s
worth having some sense of the actual size of the thing the authors are
talking about, and how implausible it all is, apart from any details of the
statistics.

[0] See figure 4 in
[https://frontiersinzoology.biomedcentral.com/track/pdf/10.11...](https://frontiersinzoology.biomedcentral.com/track/pdf/10.1186/1742-9994-10-80)

~~~
jwmerrill
To make it even more concrete: realize that the hour hand on a clock moves 6
degrees per minute (it takes 60 minutes to go all the way around, 360
degrees).

This study claims that variations of the earth’s magnetic field direction that
are more than 100 times slower than this have measurable effects on the
behavior of dogs.

~~~
smoyer
I think you meant the minute hand? The hour hand moves 0.5 degrees per minute.
I also think your parent comment meant arc-minutes.

~~~
jwmerrill
Yes, you’re right about the minute hand. Oops.

“arch minute” is a term used in the article, but “arc minute” also sounds more
standard to me.

------
nate_meurer
I have four dogs, and I watch them poop every day. For some reason they have
to slowly turn lots of circles before they're satisfied they have the best
pooping position, and if the sun is out, they almost always settle on a
position where they're not facing directly into the sun.

Makes sense from a practical viewpoint. You're more vulnerable to attack when
you're pooping out in the open, and even moreso if the sun is right in your
eyes.

To the extent that more pooping is done near the middle of the day, north-
south pooping orientation would naturally dominate. No need for a sixth
"compass" sense.

~~~
weinzierl
> Makes sense from a practical viewpoint. You're more vulnerable [..] and even
> moreso if the sun is right in your eyes.

 _" Dogs, like everyone, don't like the sun in their eyes."_ would be enough
of an explanation for me. Predators even don't like the sun in their eyes,
that's why they attack with sun behind them, if they can. Wouldn't make much
sense for the dog to turn it's back in the most likely direction a predator is
going to attack.

~~~
ramblerman
If predators attack with the sun behind them then shouldn’t dogs look into the
sun to protect themselves?

~~~
cgriswald
Dogs look to their pack for protection while doing their business. If your dog
stares at you while he's pooping, this is why. It's also why he might follow
you into the bathroom... to keep _you_ safe while you do your business.

------
remcob
You don't need any magnetic field to distinguish the north-south direction. It
is simply the direction shadows are cast when the sun is at its brightest.
Consequently, plants will have adjusted to it, providing many (subconscious)
clues. The sun makes things strongly non-isotropic, and these clues are
everywhere; in the light, in the plants, in the wind, in sound, in urban
planning, etc.

I expect most of the anecdotal 'evidence' to be explained by this. What would
compel me is if randomly changing the magnetic field correlates with the
observations, which is what this study seems to have done.

------
contravariant
I encourage everyone to read the paper linked in the article. They've gone
through surprising amounts of effort to justify their conclusion, and it
includes some surprisingly nice graphs of the 'alignment during defecation' of
dogs.

I sincerely hope their works will be recognised by the (Ig)-nobel committee.

~~~
supernova87a
I did not understand the 3 bins of 0%, 1%, 2% etc. declination. Does anyone
have a simple explanation for that?

Also, the point about the sun is good -- maybe they just don't want sun in
their eyes. Clearly the very dedicated and obsessed researcher needs to do a
similar study but indoors. Can you imagine who has the personal passion to do
this data collection?

~~~
contravariant
I don't have a particularly good explanation for those specific choices, but I
did notice that they resulted in somewhat similar sample sizes across all
three bins, so it might just have been that.

~~~
supernova87a
Oh, I meant, I don't even understand what the bins are -- what is the
declination measuring that they wanted to divide the data up by?

------
MrEldritch
hm. upon reading the paper, this is sounding _very_ suspicious.

> The study was truly blind. Although the observers were acquainted with our
> previous studies on magnetic alignment in animals and could have consciously
> or unconsciously biased the results, no one, not even the coordinators of
> the study, hypothesized that expression of alignment could have been
> affected by the geomagnetic situation, and particularly by such subtle
> changes of the magnetic declination. The idea leading to the discovery of
> the correlation emerged after sampling was closed and the first statistical
> analyses (with rather negative results, cf.Figure 1) had been performed.

Like, am I reading this wrong, or are they straight-up saying "we couldn't
achieve statistical significance on our original hypothesis, so we just went
fishing for correlations until one of them came up significant, and it turned
out to be magnetic declination"?

~~~
ncmncm
Why not? Science that insists on hypotheses written down beforehand is cargo-
cult science. Observation is the first and most productive science. Double-
blind experiments are to cement gains.

~~~
MrEldritch
basically, because once you start trying multiple hypotheses on the same
dataset, the math used to determine "is this conclusion real, or am I just
fooling myself" begins to break down.

The statistical significance threshold usually used is p<0.05, meaning that
something is (generally, this is beginning to change since the replication
crisis) considered to be a real discovery if it has less than a 1/20 chance of
being a false positive under the chosen model.

As soon as you start trying _multiple_ hypotheses, then that 1/20 chance of
being a false positive begins to become meaningless. If you can just keep
rolling d20s until one of them comes up with a critical hit, then you can
easily generate false positives that still look very robust.

This is exactly the sort of bad science - p-hacking, fishing expeditions, and
the garden of forking paths - that led to the replication crisis. (And that
makes sense, as this paper is from 2013, and predates the widespread discovery
of the crisis)

~~~
dodobirdlord
The math continues to work out as long as you use the right approach. You have
to collect twice as much data, and then set half of it aside at random without
examining it. Then you can do whatever perverse p-hacking multi-modeling
curve-fitting whatever to the half you kept until you reach a hypothesis, then
check it against the half you set aside to recover the statistical
significance you lost by using techniques that may have overfit the first
half. Unsurprisingly, the math works out because this approach is isomorphic
to collecting the first half, studying it to form a hypothesis, then
conducting a proper pre-hypothesized experiment to collect the second half.
Validation via holdout sets is the same approach used in machine learning and
elsewhere to prevent models from overfitting data.

~~~
MrEldritch
This is true! I was trying to simplify things a bit for a basic explanation,
but I fear I oversimplified. I just meant that the _generally used_ math
breaks down; if you're aware of the problem, you can correct for it, but very
often people don't.

~~~
ncmncm
Stating it more plainly, what you wrote was incorrect, and unfairly tarred a
statement that was, in fact, correct.

------
yovagoyu
The sun set/rises East/West. Maybe dogs just don't like looking directly into
the sun when they go.

~~~
dmode
What about pooping at night though?

~~~
EADGBE
Or high-noon? I have it on good suspicion that dogs can poop any time of day,
not just early morning/evening.

------
blululu
This is fun, however it seems like it would be easier and more reliable to
just put some dogs next to a gigantic magnet. There are a number of confounds
related to sunlight and other geophysical parameters (wind) that are not
controlled for in this study. A magnet would demonstrate a clear causal link
much faster than forcing some grad students to watch dogs pooping in
uncontrolled settings. Though I suppose people who own 4T magnets are probably
not cool with some random person showing up with a dozen dogs and a couple of
compost bags.

~~~
blazespin
That's the next paper I'm sure. This one was likely a study of the results and
an accidental reveal of the correlation. It's possible the correlation was
accidental though, a minor bit of p-hacking.

It'd be awesome to prove this false (if false) as it'd be a very compelling
learning study for problem of p-hacking.

~~~
aaron695
It's turtles all the way down

[http://scienceinpoland.pap.pl/en/news/news%2C80222%2Cwoof-
yo...](http://scienceinpoland.pap.pl/en/news/news%2C80222%2Cwoof-you-believe-
it-magnets-change-behaviour-defecating-dogs.html)

------
amiga_500
Should humans be doing the same? Is the failure to align toilets contributing
to increased stress? We need more research!

~~~
jaldhar
Pitch to Gwyneth Paltrow: Pooping magnets.

------
jammygit
...I used to joke with my wife this must be the case.

My dog spends so much time trying to find the right place. It’s during the
day, so it can’t be astrology, so must be leylines or the magnetic field of
the earth. Elementary really

She will get a kick out of this article for sure

~~~
lupire
If it were magnetism, it would be pretty easy for the dog to choose the
direction.

------
simonw
The thing I love about this story is that it is SUCH a dog thing to do. Dogs
would absolutely poop in alignment with earth's magnetic field. They wouldn't
need a reason to do it. It's just the kind of thing they'd do.

------
j-james
Related: in 2008 the German University of Duisburg-Essen did a study on cattle
based off of Google Earth images, with similar results.

The researchers also did field studies of deer in the Czech Republic. They
found that the vast majority (well over 2/3) aligned themselves along a
north/south or south/north meridian [1].

edit: it seems tomas_aspre found the actual publication [2].

[1]
[http://news.bbc.co.uk/2/hi/science/nature/7575459.stm](http://news.bbc.co.uk/2/hi/science/nature/7575459.stm)

[2]
[https://www.ncbi.nlm.nih.gov/pubmed/23700176](https://www.ncbi.nlm.nih.gov/pubmed/23700176)

------
c3534l
Turn it into an experiment and I'll believe it. See if you can control where
dogs poop with an elecromagnet.

------
A4ET8a8uTh0
It is interesting. Now that it was pointed out, the pattern does seem to match
our dog as well. I would love to find out more.

Mamy who saw dog select a spot are aware of the 'thrice blessed' dance.

------
salawat
I'm kind of skeptical on this one.

I find that there are far more factors that tend to take priority in the
direction our dog relieves herself. Oncoming/prevailing wind, rain, whether
she was spooked in a particular direction or not, amount of exertion (was she
running or walking before the urge hit), ambient noise, presence of echo,
presence of other animals and whether or not she feels safe around them.

I mean, it's a nice sample size, and I suppose the data is fun, but a follow
up should probably be done taking into account magnetic north is currently
hauling ass to the geospatial west and see if dog alignment changes with that.

Furthermore, where are the instances of dogs forming defecation circles around
MRI's?

No defecate based outlines of magnetic field lines, no dice in my humble
opinion. Yes. I know, I'm a stick in the mud; but if you're going to claim
something like this, that's actually a fairly easy way to confirm it. Just
head to a radiology clinic with your dog and have them do their business. You
should see wildly divergent behavior over time, because they aim to keep those
machines operating regularly, which should definitely be able to overwhelm the
Earth's ambient magnetic field in close proximity.

------
heimatau
I come to HN for the comments. You don't disappoint. I'm glad we have multiple
people whom thinking critically enough about a publication to demystify it.

Nate says it's simply primal. Eldritch talked about the cognitive bias. Etc,
etc. thanks for the critical thinking!! keep up the great work!

------
polynomial
Surprised to see this on pbs (then again, not) but a great example of anti-
science being buoyed by a sea of epistemic uncertainty. Hopefully we'll being
hearing more about this study come September at the Ig-Nobel awards, in the
category of best p-hacking.

~~~
gnicholas
*pee-hacking

------
quotemstr
My dog is obviously not a compass. This study is more about showcasing bad
research methods than anything else. (Especially if it's unintentional.) I'm
reminded of the famous dead salmon fMRI result:
[https://www.discovermagazine.com/mind/fmri-gets-slap-in-
the-...](https://www.discovermagazine.com/mind/fmri-gets-slap-in-the-face-
with-a-dead-fish)

------
archsurface
I don't have dogs, but I see people walking their dogs, and they don't give a
damn which way they're facing. Tree, bush, wall, open pavement - all fine.
They walk, they break, they walk.

------
metabagel
Instant Ig Nobel finalist.

[https://www.improbable.com/ig-about/](https://www.improbable.com/ig-about/)

------
amriksohata
This reminded me of this article in the BBC of

[https://www.bbc.co.uk/news/av/stories-51281856/electrosensit...](https://www.bbc.co.uk/news/av/stories-51281856/electrosensitivity-
i-didn-t-believe-people-had-it-then-it-happened-to-me)

and related studies behind it

[http://www.utdallas.edu/news/2016/2/3-31891_Study-
Uncovers-H...](http://www.utdallas.edu/news/2016/2/3-31891_Study-Uncovers-How-
Electromagnetic-Fields-Amplify-_story-wide.html)

[https://www.theguardian.com/science/2019/mar/18/humans-
earth...](https://www.theguardian.com/science/2019/mar/18/humans-earth-
magnetic-field-magnetoreception)

Basicaly in nearly all Hindu texts, when praying or doing Yoga they tell
people to face East/the sun, so that your magnetic field is aligned as
unaligning it risks disease.

The team say modern environments would likely interfere with this “sense”,
while there is no sign as yet that such a system is linked to human
consciousness, or that it influences our behaviour – although the team say it
remains a possibility, and are planning experiments to find out.

I wonder if dogs almost feel a need to align with field in the right way to
feel comfortable.

------
HappyDreamer
I wonder how the researchers came up with the idea to study this.

Anyway, this is good news? Dogs are more similar to humans, than what birds
are, right. Maybe there's a magnetic field sensing dog gene that can be copied
to humans? So that at least the future generations won't lose their
orientation, as fast as I do, in the streets and indoor shopping malls.

~~~
James_Henry
There is a human neural response to magnetic fields:
[https://www.sciencedaily.com/releases/2019/03/190318132646.h...](https://www.sciencedaily.com/releases/2019/03/190318132646.htm)

~~~
HappyDreamer
> revealed a decrease in alpha-band brain activity -- an established response
> to sensory input -- in some participants

Interesting this happened in only _some_ participants.

Makes me wonder about sensing fields caused by electricity or the very weak
fields caused by flowing water (which tends to contain some salt ions /
charged particles).

~~~
HappyDreamer
Edit: flowing water = no fields, because plus and minus ions evens out, no net
charge. However if one is small as a molecule and really close to the water,
then I suppose one would feel the fields of individual dissolved salt ions
passing by

------
jb775
I just grabbed my compass to check...can confirm that my black lab Piper's
recent poops have been north/south. Now that I think of it, I can't remember a
time she hasn't been facing north/south...no matter the weather or time of
day.

------
geuis
I’m a real skeptic on this. I’ve had dogs my whole life and they just shit any
which way they want.

There have been no follow up studies that I can find to replicate this
“experiment”.

Searching around just finds lots of duplicate stories in the old echo chamber
based on the original paper.

~~~
Ididntdothis
I think it depends on the dog. Mine circles several times until she has found
the perfect spot. Some fosters we had would just throw down wherever. I’ll
definitely watch the direction next time.

~~~
pbhjpbhj
When I saw this, my first thought was that circling could allow magnetic
alignment.

~~~
mthoms
They do the same before lying down. It's never been understood exactly why
that is.

~~~
dx87
The reason I've read is that it's a leftover from when they lived in the wild,
and it would help make sure they don't lay down on top of something dangerous,
like a snake or ant colony. It would also make since to do it before pooping
since they're going to be in a vulnerable position.

------
tuesday20
Would be nice to know if there is any other reason, other than “don’t like sun
in my eyes”.

I remember during the tsunamis, animals knew something is gonna happen and got
restless. I wonder how much of these intuition and senses humans have lost, by
tuning out nature

------
xenospn
Anecdotally, I actually tested this one time. I pulled out my phone and
launched the compass app. My dog was PERFECTLY aligned and was facing north
while pooping. Never tested it again, tho. But if it was a fluke, it was a
very impressive one.

------
aaron695
I simply don't believe this study. And this stuff is important, how animals
including us interact with the magnetic field is not a small thing. 6 years
later it needs backing.

Anyway if you too want to interact with Earth’s magnetic field in a stronger
way you can augment like this -

"For six weird weeks in the fall of 2004, Udo Wächter had an unerring sense of
direction. Every morning after he got out of the shower, Wächter, a sysadmin
at the University of Osnabrück in Germany, put on a wide beige belt lined with
13 vibrating pads"

[https://www.wired.com/2007/04/esp/](https://www.wired.com/2007/04/esp/)

I'd like to hear an impartial experience on this, it seems interesting but
like putting magnets in your fingers after all that effort people tend to
exaggerate the experience. I think a Kickstarter was tried around it.

------
aj7
My wife, who can barely read a map, has such good directional sense that I am
convinced that attoampere(?) currents induced in her brain as she cuts through
the earth’s magnetic field are interpretable by her and form memories.

------
k__
What are the applications if we would breed dogs based on that "skill"?

~~~
Waterluvian
We could breed homing dogs that can find their way home by following the
treasure trail they left behind.

~~~
quickthrower2
Well they have a good sense of smell already so the magnetic aspect probably
wouldn’t add much.

------
tomas_aspre
Hope this gains traction - imagine the societal consequences of optimizing
human magnetic alignment in city planning and building/room layout.

Also interesting and relevant:

Magnetic alignment contributes to difficulty falling asleep (north-south
alignment is best)
[[https://www.researchgate.net/publication/280093617_The_Relat...](https://www.researchgate.net/publication/280093617_The_Relationship_between_Quality_of_Sleep_and_Geographical_Directions_during_Sleeping_Process)]

Grazing cattle align on north-south axis
[[https://www.ncbi.nlm.nih.gov/pubmed/23700176](https://www.ncbi.nlm.nih.gov/pubmed/23700176)]

~~~
yoavm
Is it just me or is it really weird to start a scientific paper with "sleep
has been one of God’s most precious blessings since human’s existence and it
is vital for both body and soul"?

~~~
schoen
It reminds me of a line in "The Rime of the Ancient Mariner":

[https://www.litscape.com/author/Samuel_Taylor_Coleridge/The_...](https://www.litscape.com/author/Samuel_Taylor_Coleridge/The_Rime_Of_The_Ancient_Mariner_Part_5.html)

------
lowdose
This is an American study and a lot of cities in the USA have a street grid
with the orientation North - South. It could be dogs orientate position on the
wind axis.

------
alexilliamson
I just want to say that these are some of the most fun comments I've seen in a
while on an HN thread. Thanks everyone and make sure your toilets are aligned!

------
lonelappde
Considering all the cases that were excluded, and the imprecision inherent in
measuring poop direction, N is pretty low here.

------
huffmsa
Now that you mention it, my childhood dog almost always faced mostly north or
south when conducting her business

------
erickhill
Is this why some folks think dogs seem to be able to predict earthquakes? They
have some built-in connection?

~~~
ncmncm
Earthquake build-up produces electric fields.

It would be a different sensory system.

------
blazespin
To be fair, this is pretty common in animals.
[https://www.momtastic.com/webecoist/2008/09/18/animal-
magnet...](https://www.momtastic.com/webecoist/2008/09/18/animal-magnetism-
the-amazing-and-weird-ways-animals-are-affected-by-the-earths-magnetic-field/)

It's quite possible.

------
paulgrimes1
My partner after me speaking about this, with zero irony: “I think that study
is a load of shit”

------
jackcosgrove
Dogs circling to poop, puts a new spin on the idea of the lodestone.

------
cgriswald
Did they have a control group pooping inside a Faraday cage?

~~~
unsrsly
Fun fact: Faraday cages don't block low frequency magnetic fields. But mu
metal and active magnetic shielding can :)

------
shd4
God damnit, that made me laugh. Beautiful creatures.

------
nebulous1
I'm so glad somebody is finally looking into this

~~~
thisisnico
Tax dollars well spent!

~~~
numlock86
Czech tax dollars to be accurate.

~~~
yread
The study was supported by the Grant Agency of the Czech Republic (project.
nr. 506/11/2121)

------
lonelappde
You could answer this research question much more accurately by building an
app and collecting data from users mobile devices.

------
tribeofone
LOVE weekend posts on HN!

------
jimnotgym
I think the authors need a reminder that coprology does not imply causation.

------
ebg13
2013/2014

------
yovagoyu
Tax dollars.

------
totalZero
Twelve authors on a paper about dog poop.

And people wonder why academia isn't taken seriously by normal people...

------
fallingfrog
Or maybe, dogs just don’t like to look straight into the sun when they poop,
which rises in the east and sets in the west. Good grief. Sometimes the
smartest people are also the dumbest. Would you stare right at the sun when
pooping?

~~~
mmastrac
They tested for that:

> The fact that larger and faster changes in magnetic conditions result in
> random distribution of body directions, i.e., a lowering of the preferences
> and ceasing of the avoidances, can be explained either through disturbing or
> conscious “shutdown” of the magneto-reception mechanism.

~~~
fallingfrog
I’ll bet if you repeated the whole thing on cloudy days only the effect would
go away. You’d have to have very very strong evidence that dogs have some
sensory organ that detects magnetic fields when the sun is right there in the
sky and explains the effect in a way that is obvious to everyone.

~~~
eganist
> I’ll bet if you repeated the whole thing on cloudy days only the effect
> would go away. You’d have to have very very strong evidence that dogs have
> some sensory organ that detects magnetic fields when the sun is right there
> in the sky and explains the effect in a way that is obvious to everyone.

again, pages 5-6:

> Even if we would assume that these sunshine hours were evenly distributed
> over the daylight period and the year (as our observations were),there would
> only be a probability of 33% that the observation was made when the sun was
> visible. Hence,with high probability (67%) most walks during the day-light
> period were made when it was cloudy.

There's wisdom in reading the study before commenting further considering your
specific rebuttals have all been addressed in the source material. There were
_literally_ nearly 7,500 measurement events factored into this study, the
majority of which were likely cloudy given the location.

~~~
fallingfrog
_Likely?_ so let me get this straight, they didn’t even _record_ which days
were sunny? Extraordinary claims and all that. Sorry but I’m right about this
no matter how many downvotes I get.

~~~
eganist
> _Likely?_ so let me get this straight, they didn’t even record which days
> were sunny? Extraordinary claims and all that. Sorry but I’m right about
> this no matter how many downvotes I get.

Please just read the paper. Events were timestamped, aggregated over two
years, and took place at all times of day (including well after dark) with the
same outcome.

Disengaging. Cheers, friend.

