# Why are cows magnetic? **URL:** \ **Category:** Factual Questions\ **Created:** [April 2, 2012, 4:39am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552 "2012-04-02T04:39:19Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Chessic\_Sense](https://avatars.discourse-cdn.com/v4/letter/c/7c8e57/32.png) [@Chessic\_Sense](https://boards.straightdope.com/u/Chessic_Sense)\ **Post date:** [April 2, 2012, 1:00pm UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/21 "2012-04-02T13:00:44Z")
> [@Grey](#): > > Oh it was better than that - [μ](http://en.wikipedia.org/wiki/Vacuum_permeability) I thought he was going for [magnetic moment](http://en.wikipedia.org/wiki/Magnetic_dipole_moment). ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [April 2, 2012, 2:05pm UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/22 "2012-04-02T14:05:52Z")
> [@robert\_columbia](#): > > Mu > [@Dervorin](#): > > _Golf clap_ > > I feel it deserved at least that much attention. However, the fact that there’s no element with the symbol Mu does rather spoil the joke, tragically. there is Mu-metal an alloy with high magnetic permeability. might not have been aimed for though it hit the target anyway. ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [April 2, 2012, 2:12pm UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/23 "2012-04-02T14:12:32Z")
> [@johnpost](#): > > could be interaction with the cow magnets. Damn, you stole [the joke I was going to make.](http://en.wikipedia.org/wiki/Cow_magnet) ---
**Author:** ![Malleus\_Incus\_Stapes](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/malleus_incus_stapes/32/3293_2.png) [@Malleus\_Incus\_Stapes](https://boards.straightdope.com/u/Malleus_Incus_Stapes)\ **Post date:** [April 2, 2012, 2:50pm UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/24 "2012-04-02T14:50:04Z")
> [@Dervorin](#): > > _Golf clap_ > > I feel it deserved at least that much attention. However, the fact that there’s no element with the symbol Mu does rather spoil the joke, tragically. I thought he was speaking in [Zen](http://www.straightdope.com/columns/read/43/what-is-the-sound-of-one-hand-clapping). ---
**Author:** ![Corcaigh](https://avatars.discourse-cdn.com/v4/letter/c/eb8c5e/32.png) [@Corcaigh](https://boards.straightdope.com/u/Corcaigh)\ **Post date:** [April 2, 2012, 4:58pm UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/25 "2012-04-02T16:58:11Z")
> [@Reply](#): > > All over the world, apparently cattle herds tend to orient themselves along a north-south axis. I don’t think I’ve ever noticed the cows around here only ever pointing on direction. I shall be on the lookout for this phenomenon and ask the dairy farmers that I know if they do! ---
**Author:** ![coremelt](https://avatars.discourse-cdn.com/v4/letter/c/4491bb/32.png) [@coremelt](https://boards.straightdope.com/u/coremelt)\ **Post date:** [April 2, 2012, 5:01pm UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/26 "2012-04-02T17:01:56Z")
This is relevant: > **[summitcountyvoice.com](http://summitcountyvoice.com/2012/04/01/study-traces-genetic-origins-of-cattle/)** > > This domain may be for sale! ---
**Author:** ![hogarth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hogarth/32/1773_2.png) [@hogarth](https://boards.straightdope.com/u/hogarth)\ **Post date:** [April 2, 2012, 5:47pm UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/27 "2012-04-02T17:47:52Z")
There was an episode of William Shatner’s TV show “Weird or What?” where they investigated the claim. They weren’t able to replicate it, I think. ---
**Author:** ![Zulema](https://avatars.discourse-cdn.com/v4/letter/z/db5fbb/32.png) [@Zulema](https://boards.straightdope.com/u/Zulema)\ **Post date:** [April 2, 2012, 6:28pm UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/28 "2012-04-02T18:28:03Z")
> [@MrDibble](#): > > Has the study taken into account that the path of the Sun is generally E-W? So if you want to be warmed up by it, it pays to have your flanks to it. I was thinking this also. If the cow wants the most amount of warmth on her skin she’ll turn her side to the sun but that doesn’t explain why in one group they always seem to be facing the same way and not facing each other occasionally. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [April 2, 2012, 6:55pm UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/29 "2012-04-02T18:55:31Z")
Of course they all face the same way: They’re herd animals, and their greatest defense is the stampede. When everyone’s facing the same way, you’re ready to stampede at a moment’s notice, while if some were facing the other way, they’d just get in each others’ way come stampeding-time. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [April 2, 2012, 7:51pm UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/30 "2012-04-02T19:51:52Z")
Even if cows do have a magnetic sense, that really does not explain why they would habitually use it to align themselves with the geomagnetic field. Do the birds that are actually known to have a magnetic sense align themselves with the field when they are not actually migrating? I doubt it. Furthermore, one would expect that the apparently widespread use of [cow magnets](http://en.wikipedia.org/wiki/Cow_magnet) (which, I must admit, I only just learned about from **johnpost** ’s and **MikeS** ’s posts, above), would mess with any magnetic sense the cattle might naturally have. IIRC, magnetic sense in migratory birds was discovered when it was found that fixing a magnet to a bird messed up its sense of direction. The geomagnetic field is weak, and a strong alnico in a cow’s stomach ought to plenty enough to mess up any magnetic sense that might be there. The suggested explanations in terms of prevailing wind or the direction of the Sun seem much more plausible (or, you know, it could all be just good old statistical artifact). It seems likely that cattle would be most in need of being warmed by the Sun in the morning, so they would tend to line up north-south then, to get it on their flank. By middle day, they might be warm enough, and not care, or even might want to avoid heating up much more and thus _not_ want the Sun on their flank (which would again align them north-south). Note, also, that the result is not claiming to be more than a statistical, on-the-whole tendency, and I doubt whether they controlled for time of day when the satellite photos were taken, so cows facing randomly when it is not morning would probably just be written off as statistical noise. ---
**Author:** ![Siam\_Sam](https://avatars.discourse-cdn.com/v4/letter/s/d78d45/32.png) [@Siam\_Sam](https://boards.straightdope.com/u/Siam_Sam)\ **Post date:** [April 3, 2012, 1:43am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/31 "2012-04-03T01:43:11Z")
> [@johnpost](#): > > could be interaction with the cow magnets. This could have positive (heh) implications for high-school students and frat boys in their cow-tipping endeavors. ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [April 3, 2012, 2:32am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/32 "2012-04-03T02:32:10Z")
> [@njtt](#): > > Furthermore, one would expect that the apparently widespread use of [cow magnets](http://en.wikipedia.org/wiki/Cow_magnet) (which, I must admit, I only just learned about from **johnpost** ’s and **MikeS** ’s posts, above), would mess with any magnetic sense the cattle might naturally have. I’d only heard of “Cow Magnets” as a _Far Side_ joke; I’d no idea there actually _were_ things called cow magnets. ---
**Author:** ![Reply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/reply/32/15952_2.png) [@Reply](https://boards.straightdope.com/u/Reply)\ **Post date:** [April 3, 2012, 3:21am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/33 "2012-04-03T03:21:01Z")
I wonder if we can herd them with electromagnetic UAVs. ---
**Author:** ![jasg](https://avatars.discourse-cdn.com/v4/letter/j/f0a364/32.png) [@jasg](https://boards.straightdope.com/u/jasg)\ **Post date:** [April 3, 2012, 4:36am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/34 "2012-04-03T04:36:25Z")
> [@cmyk](#): > > I can’t stand the Insane Cow Posse. Especially with guns… [http://www.youtube.com/watch?v=FQMbXvn2RNI](http://www.youtube.com/watch?v=FQMbXvn2RNI) ---
**Author:** ![ruh-roh](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@ruh-roh](https://boards.straightdope.com/u/ruh-roh)\ **Post date:** [April 3, 2012, 4:57pm UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/35 "2012-04-03T16:57:25Z")
> [@njtt](#): > > Furthermore, one would expect that the apparently widespread use of cow magnets… would mess with any magnetic sense the cattle might naturally have. I’m thinking it is the cows without magnets that stand pointing in semi-random directions. It is the ones with magnets that get pulled around to align with the magnetic field. What really pisses them off is the migrating birds that keep crashing into them. 😃 ---
**Author:** ![purplehorseshoe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/purplehorseshoe/32/2996_2.png) [@purplehorseshoe](https://boards.straightdope.com/u/purplehorseshoe)\ **Post date:** [April 3, 2012, 4:57pm UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/36 "2012-04-03T16:57:51Z")
> [@rachelellogram](#): > > Is it so the breeze doesn’t blow their tail hair back into their butts when they poop? > > Hehe, there’s a [cowlick](http://i.imgur.com/v7HST.png) in Nebraska right now. Ha! I never thought of that. 🙂 In all seriousness, though, I believe it’s so the wind isn’t blowing into their faces - nostrils and eyes, especially. ---
**Author:** ![TimeWinder](https://avatars.discourse-cdn.com/v4/letter/t/bcef8e/32.png) [@TimeWinder](https://boards.straightdope.com/u/TimeWinder)\ **Post date:** [April 5, 2012, 3:18am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/37 "2012-04-05T03:18:20Z")
> [@cmyk](#): > > [Here’s a cool “wind map”](http://hint.fm/wind/index.html) of the US that indicates wind direction from day to day. > > Let it load for a minute, it traces out wind currents across the map; the results are actually really cool and fascinating. Makes America look furry. Which leads directly to the best-named result in science: the [hairy ball theorem](http://en.wikipedia.org/wiki/Hairy_ball_theorem). Based on more or less the same observation you just made, it’s a proof that there must, at any given time, be a location of zero wind somewhere on the earth. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [April 5, 2012, 5:20am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/38 "2012-04-05T05:20:39Z")
Or of discontinuous wind. ---
**Author:** ![Reply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/reply/32/15952_2.png) [@Reply](https://boards.straightdope.com/u/Reply)\ **Post date:** [April 5, 2012, 6:59am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/39 "2012-04-05T06:59:34Z")
So we’ve got: 1. Cows are magnetic because people have tailbones (i.e. evolution isn’t 100% clean) 2. Cows don’t like to poop into the wind 3. Cows like to sunbathe 4. SOME cows are magnetic and the rest like to stampede I might have to make this my senior thesis, heh. ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [April 5, 2012, 11:59am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/40 "2012-04-05T11:59:22Z")
> [@TimeWinder](#): > > Which leads directly to the best-named result in science: the [hairy ball theorem](http://en.wikipedia.org/wiki/Hairy_ball_theorem). Since it involves cyclones, I wonder if that theorem is popular in [Fort Wayne](http://en.wikipedia.org/wiki/Harry_Baals). [Previous page](https://boards.straightdope.com/t/why-are-cows-magnetic/617552.md?page=1) [Next page](https://boards.straightdope.com/t/why-are-cows-magnetic/617552.md?page=3)