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Giant African Rat Kills With Poisonous Mohawk

Posted by samzenpus on from the T-approved dept.

thebchuckster writes "The African crested rat has been known to kill local dogs, but researchers have just figured out how. After eating the 'poison-arrow plant,' the over-sized rodent stores its poison-laced spit in special hollow hairs in its mohawk. Then, when a predator grabs the rat, the animal gets stung with the poison and spit-tipped hairs which can sicken and kill."

66 of 97 comments (clear)

  1. Punk by ctrimm · · Score: 2

    Now that's punk.

    1. Re:Punk by Abreu · · Score: 1

      More like a randomly generated Gamma World character

      "Poisonous / Ratman"

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    2. Re:Punk by flyneye · · Score: 1

      We're breeding it into our next gen Marine stock. Semper Fi!

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    3. Re:Punk by hairyfeet · · Score: 1

      Yeah what idiot in the animal kingdom gonna mess with this baaaad mofo, he's a rat with a mohawk! The fact that its poison just shows he's a rat that takes NO shit from nobody. I bet he's got a little switchblade to, just ready to stab your ass if you piss him off. he's a baaaad little rat dude!

      --
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    4. Re:Punk by hesaigo999ca · · Score: 1

      Now that's Spunk ....there ...fixed that for you.

  2. Is this tool use? by es330td · · Score: 2

    I realize it isn't termite fishing with a stick like monkeys do but it is certainly manipulation of an object for the animal's benefit.

    1. Re:Is this tool use? by blair1q · · Score: 1

      Only if the rat bought the quills at the Home Depot.

    2. Re:Is this tool use? by Chris+Burke · · Score: 2

      I wouldn't call chewing bark tool use. Nor grooming. It's "manipulation" only in the broadest sense of "using", but eating food is "using" an object for the animal's benefit.

      Regardless of semantics, it is doubtful this is a sign of intelligence (which tool use is usually taken to suggest).

      However it is a sign of awesome. Punk rock murder rats? Hell yes.

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      The enemies of Democracy are
    3. Re:Is this tool use? by shugah · · Score: 1

      The article says the behavior seems to be hardwired into the rat's brain; that is, it's instinctive.

      Chimpanzees have to be taught to fish for termites with a stick. Chimps don't have any evolutionary adaptation specific to fishing for termites (an opposable thumb is not specific to this behavior or even to primates). My understanding is that some populations of chimps (and even individuals within a population) learn / exhibit this behavior, others don't.

      The giant crested rat chews poison bark and grooms its specially adapted crest hairs instinctively. Rats don't need to be taught to chew, or to groom. While it is a little more involved (requires a specific behavior or chewing and grooming) it is very similar to a poison dart frog absorbing, concentrating and sequestering in their skin, toxins from centipedes, ants etc. that they eat. My guess is that all giant crested rats, in an environment where this tree is native, would exhibit the same chewing and grooming behavior.

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  3. How did this evolve? by improfane · · Score: 3, Interesting

    It does make you wonder how something so specific could evolve, the relationship between a poisonous plant and then the distribution mechanism.

    I know that when I eat certain herbs, I sweat them out and smell strongly of that herb whereas other people I know are fine. I wouldn't be surprised if that is related, the rats that could not sweat out the chemicals died, those that could survived, the ones who sweated through barbs fared even better. Do animals that disperse poison even know it's a defensive mechanism?

    How can they evolve that knowledge? Or is it aggression that is evolved too? A poisonous rat that is passive will probably not survive (it might still get eaten if it kills its predator) whereas one that is aggressive can attack its predator before it eats it.

    What do you think?

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    1. Re:How did this evolve? by JeanInMontana · · Score: 1

      It's a basic instinct to survive, I doubt the rats are aggressively using anything. Predator grabs rat to kill and the poison is released.

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    2. Re:How did this evolve? by NiceGeek · · Score: 1

      Look up what a scientific theory entails and maybe you can post without someone calling you an imbecile. Intelligent Design isn't even a decent hypothesis, let alone a theory. You're the one with a closed mind.

    3. Re:How did this evolve? by Anonymous Coward · · Score: 1

      I'd like to encourage you to watch Professor Kenneth Miller of Brown University speaking at Case Western Reserve University. Every irreducible complexity argument has been debunked, and if you were to argue that this rat's unique ability is evidence of irreducible complexity, I'm sure it would be too. There have been many other instances that were much more convincing than this rat, all of which have been explained to my satisfaction and the satisfaction of most of the scientific community. Some of these very compelling instances are beautifully explained by Professor Miller in this video.

    4. Re:How did this evolve? by willy_me · · Score: 1

      How can they evolve that knowledge? Or is it aggression that is evolved too? A poisonous rat that is passive will probably not survive (it might still get eaten if it kills its predator) whereas one that is aggressive can attack its predator before it eats it.

      In this example, aggression is not required. If an animal is killed but also kills the predator in the process, then the DNA of that animal will be more likely to survive via the increased likelihood of survival for it's relatives due to the death of a local predator.

      For example, mother and baby rats get attacked by a fox. One baby rat dies along with the fox. Now the mother and remaining babies have an increased chance of survival. Because they all share similar DNA, the DNA traits that killed the fox survive.

    5. Re:How did this evolve? by Heed00 · · Score: 1

      Right, so here we see the mighty argument from design -- "It's complex therefore it had a designer."

      It's a complete non-sequitur. One simply doesn't follow from the other. Designers can design simple things and complex things can arise without a designer.

      You complain about open minds but provide no actual argument -- you do what everyone who has ever put forward the argument from design or one of its variants does -- you go, "See, see this complex thing! Doesn't that blow your mind? Yep, it just makes sense that something made it, right? Right?" And you do that because there is no actual argument to make -- it's just a trick of the light.

      --
      Thought thinks itself.
    6. Re:How did this evolve? by Translation+Error · · Score: 1

      Because the THEORY of Evolution is merely a man-made attempt to push God out of their lives. This is yet another example of Intelligent Design. Anyone who examines the INCREDIBLE COMPLEXITY of living things should be able to realize that these are examples of intelligent design. Symbiotic relationships, even moreso.

      Yes, the theories all those scientists have come up with, pieced together from many data and refined time and time again to account for new data, has nothing against your assertion backed by "BECAUSE I SAID SO."

      Really, why do they even bother scrounging around in the dirt to come up with some absurd theory of 'evolution' when any fool can see--wait, that sounds familiar somehow...

      --
      When someone says, "Any fool can see ..." they're usually exactly right.
    7. Re:How did this evolve? by Darth_brooks · · Score: 1

      People seem to think evolution is akin to this situation: "I was walking down third street just past the bank when I looked down and found a 1999 series A twenty dollar bill that happened to appear on the ground about six inches from the no parking sign, so I picked it up and put it in my left pants pocket." Evolution is more along the lines of "I found some money on the ground."

      In this case, the rats probably evolved the hollow hairs for a reason (IIRC these aren't uncommon in the animal kingdom. Isn't polar bear fur the same way? A series of (hollow) tubes?), the plant evolved poison for obvious reasons, and the two working together is more a case of happy natural symbiosis than it is plain old fashioned evolution.

      I'm curious if the plant chewing and bathing routines are unique to just this rat, or if they all do it.

      --
      There are some people that if they don't know, you can't tell 'em.
    8. Re:How did this evolve? by Macgrrl · · Score: 1

      I blame Douglas Adams, the Bablefish proof is obvious prior art for the concept of Intelligent Design.

      With a bit of luck they will all get knocked down at a zebra crossing. :P

      --
      Sara
      Designer, Gamer, Macgrrl in an XP World
    9. Re:How did this evolve? by Chris+Burke · · Score: 1

      I'm having a hard time telling whether this is a troll

      Are you really?

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      The enemies of Democracy are
    10. Re:How did this evolve? by Heed00 · · Score: 1

      Hehe.

      Yeah, but the Babelfish proof actually disproves god and he vanishes in a puff of logic. ;) Wish these ID'ers would do the same.

      --
      Thought thinks itself.
    11. Re:How did this evolve? by flibbidyfloo · · Score: 2

      I know that when I eat certain herbs, I sweat them out and smell strongly of that herb whereas other people I know are fine. I wouldn't be surprised if that is related, the rats that could not sweat out the chemicals died, those that could survived, the ones who sweated through barbs fared even better.

      This is a common mistake made by people with a poor understanding of anatomy. Toxins in your body are excreted by your liver and intestines, not your skin.
      Your sweat glands are there to regulate your temperature and are in no way designed to expel toxins.

      People smell like things they've eaten because it's on their breath and on their hands.

    12. Re:How did this evolve? by flibbidyfloo · · Score: 2

      It does make you wonder how something so specific could evolve, the relationship between a poisonous plant and then the distribution mechanism.

      I wouldn't be surprised if that is related, the rats that could not sweat out the chemicals died, those that could survived, the ones who sweated through barbs fared even better.

      Oh, and rats do not sweat. They regulate their temperature by constricting or expanding blood vessels in their tails.

    13. Re:How did this evolve? by M0j0_j0j0 · · Score: 1

      Because the THEORY of Evolution is merely a man-made attempt to push God out of their lives. Let me fix this for you, Because the THEORY ( Intelligent Design) is merely a man-made attempt to push ( Science ) out of their lives. There, now you have it :)

    14. Re:How did this evolve? by Vaphell · · Score: 1

      http://en.wikipedia.org/wiki/Garlic
      Garlic is known for causing halitosis, as well as causing sweat to have a pungent 'garlicky' smell, which is caused by allyl methyl sulfide (AMS). AMS is a gas which is absorbed into the blood during the metabolism of garlic; from the blood it travels to the lungs (and from there to the mouth, causing bad breath) and skin, where it is exuded through skin pores.

    15. Re:How did this evolve? by Chris+Burke · · Score: 4, Interesting

      Polar bear fur isn't hollow, but it is transparent, and directs sunlight down to the bear's skin like a coat of fiber optic cables, which is basically what they are.

      But yeah, this isn't that unusual. Chewing and grooming are normal behaviors for rats. The hairs could have evolved for any number of reasons, and may have been quite different, maybe just specialized whiskers, before the poison plant made predator-poisoning the main selective pressure.

      There's other cases of this kind of thing. For example, hummingbirds and the flowers they feed from will often undergo runaway evolution where the hummer's bill will be specialized to feed on the flower's specialized form that only the hummer's bill will fit. Even more amazing, there's a species on a Caribbean island where the males and females aren't just different in plumage, but also very different in bill shape which is unusual. Each of the two sexes feeds exclusively from two different but closely related species of flower.

      The theory was that when the hummers first arrived on the island, there was only one species of flower, and the more aggressive males monopolized the flowers that had the highest nectar output while the females were stuck with the ones with lesser output. The result was that the higher output plants were cross-pollinated by the males while the lower output plants were pollinated by the females, setting the stage for the two populations of flowers to begin diverging into separate species, and for each sex of hummer to follow.

      I dunno, I thought that was neat.

      --

      The enemies of Democracy are
    16. Re:How did this evolve? by Hognoxious · · Score: 1

      Really? I know if I eat curries/tajines with a lot of fenugreek in them the smell is strongest in my armpits.

      --
      Confucius say, "Find worm in apple - bad. Find half a worm - worse."
    17. Re:How did this evolve? by flibbidyfloo · · Score: 1

      http://en.wikipedia.org/wiki/Garlic
      Garlic is known for causing halitosis, as well as causing sweat to have a pungent 'garlicky' smell, which is caused by allyl methyl sulfide (AMS). AMS is a gas which is absorbed into the blood during the metabolism of garlic; from the blood it travels to the lungs (and from there to the mouth, causing bad breath) and skin, where it is exuded through skin pores.

      Yes, ok, some exogenous organic compounds make their way into sweat. But garlic is not a toxin, and the gas that gets to your pores is a byproduct, not a design feature of sweat glands. Since you obviously know how to use wikipedia, try reading the one on perspiration.

    18. Re:How did this evolve? by ImprovOmega · · Score: 1

      OMG! Dude, that is waaaaaay TMI. I know this is slashdot, but c'mon.

    19. Re:How did this evolve? by AngryNick · · Score: 1

      It does make you wonder how something so specific could evolve

      First of all, the rat (Lophiomys imhausi) evolved into a non-rat, with a nice, cute, fluffy tail (see exhibit A. That prevented them from being killed by humans. The poison quill adaption was just to piss off dogs.

    20. Re:How did this evolve? by improfane · · Score: 1

      No.

      I can eat foods that do not taste of a herb with a knife and fork and my skin smells very strongly of the herb - even if you could not smell the herb in the food.

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    21. Re:How did this evolve? by shugah · · Score: 1

      This isn't exactly co-evolution because the toxin in the tree bark has evolved independently from the rat for reasons that benefit the tree - there is no co-dependence. Try co-evolution is where the dependency is mutual - such as with flowers and specific pollinators evolving together.

      --
      If you aren't part of the solution, then there is good money to be made prolonging the problem
    22. Re:How did this evolve? by blind+biker · · Score: 1

      If you read the fucking article, you'd know these weird rats chew the bark of the plant and then lick their fur to store the poison on it. They don't sweat the poison out.

      --
      "The agriculture ministry is not in charge of Gundam" - Japanese ministry official.
    23. Re:How did this evolve? by furbearntrout · · Score: 1

      It's called Poe's Law. No matter -- flamebait and troll are both -1.

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    24. Re:How did this evolve? by rubycodez · · Score: 2

      But he can never hate you as much as God does, sinner.

      Now repent and send me money for telling you so.

    25. Re:How did this evolve? by rubycodez · · Score: 1

      I see your Intelligent Design in the puddles outside my house. There is no way those puddles could so perfectly fit into those marvelously complex holes, without a Divine Puddle Maker lovingly creating and crafting them so. And when a puddle dies in the hot sun, it rises into puddle heaven and is born again to rain back. Praise the DPM! No, not Double Penetration. Mouth, you filthy heathen....

    26. Re:How did this evolve? by rubycodez · · Score: 1

      Does this give you a breeding advantage?

    27. Re:How did this evolve? by improfane · · Score: 1

      If you read the article, they still don't know why they don't die when they chew the bark.

      Idiot.

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    28. Re:How did this evolve? by Genda · · Score: 2

      That's because there are a lot of folks out there who have little tolerance for other people's belief. By the way that goes both ways. There were people burning each other over toasty coals because they disagreed on the finer points of Jesus, long before science nerds heckled the faithful. In fact the holiest church in all of Christendom, the Church of the Holy Sepulcher, has for generations had its door locked and unlocked by a Muslim family because the various sects of Christianity don't trust each other enough to give any one the keys. That my friend is being human.

      So there is faith and then there's science. One is based on the unexplainable, and the other on empirical fact and data. The reason people get pissy about ID, is because its a belief looking for justification. That's really bad science, and when they catch scientists doing that (which happens every so often) they get their hands slapped and lab coats handed to them.

      We now have so large a body of evidence, from so many fields (biology, material science, computer science, biiochemistry... it goes on and on) that we can actually point right at evolution as it happens/happened both micro and macro-evolution. Intelligent Design simply isn't necessary. If you choose to believe in God, you should be all the more joyful at your Lords cunning and brilliance to create space time that would result in atoms such that they can assemble themselves into mountains, or stars, or people. Its like epicycles, as long as you assume the earth is the center of the universe, you have to go through all kinds of ridiculous gyrations and complications to account for the behavior of the universe. The instant you give up trying to make it fit your pictures and just appreciate it the way it is, natural order arises and is self evident.,

      I have no problem with people who believe in God. Science suggests a God isn't necessary for this universe to happen the way it happens/happened. Maybe God doesn't have an ego problem? That's where the faith comes in, eh?... Bon Apetite.

    29. Re:How did this evolve? by tehcyder · · Score: 1

      I have to post this as "A.C." because if I use my real ID, the retribution is intense!

      Hold on a sec, if real Intelligent Design is yours, you must be God. Now there's a first, the supreme deity posting on slashdot. Although you'd expect Him to have a slashdot account so that He can do some proper smiting to us unbelievers.

      --
      To have a right to do a thing is not at all the same as to be right in doing it
    30. Re:How did this evolve? by guruevi · · Score: 1

      There is no such thing as macro-evolution. The rat doesn't all of a sudden start eating poisonous plants and sweating them out.

      Most likely the selective pressure was made in several small steps:
      - There is less food at one point and the only thing left is poisonous plants. Some die of the plant, some die of hunger. Those that are somewhat 'immune' to the poison get to breed.
      - If there is less food for the rats, there is usually less food for the rest of the ecosystem as well. Things start eating or bringing to their kids the rats that are still alive (most animals don't eat carcasses). Some rats have groomed after eating the poisonous plants and thus are better at not being eaten thus they can breed.
      - As time goes on, certain rats that bring out the poison better (sweating, length of arms for grooming, certain hair types that hold on to the poison better) have better survival rates and get to breed.

      The thing is it doesn't even have to happen this way. I don't know the details about this rat but it could be that the hollow hairs evolved for an entirely different purpose. If the climate was dry, this might've been better at catching dewdrops to drink etc. etc.

      Evolution is hard and the whole 'tech path' isn't always available to us (or we're simply not interested or we haven't investigated it yet) yet we can make conjectures based on the time and place of where we find a preserved ancestor specimen or DNA analysis reveals who it's cousins are in other areas.

      --
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    31. Re:How did this evolve? by Chris+Burke · · Score: 1

      Nevermind, I guess my info was outdated and wrong.

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      The enemies of Democracy are
    32. Re:How did this evolve? by retchdog · · Score: 1

      unfortunately, yes.

      --
      "They were pure niggers." – Noam Chomsky
    33. Re:How did this evolve? by Chris+Burke · · Score: 1

      Well let me help you out -- regardless of what else that post was, whether earnest or in jest, it was definitely a troll.

      --

      The enemies of Democracy are
    34. Re:How did this evolve? by flibbidyfloo · · Score: 1

      I'm not sure which one of us you are saying it disagrees with, but if it's me, I'll have to disagree in turn with your reading of the linked article.

      The key point I see is that while 8 compounds of the total 44 identified in sweat are associated with fenugreek consumption, none of them were determined by the olfactory experts to have a related odor.

      The only GC zone characterized as having that odor was an unidentifiable substance. The researchers *merely speculated* that it might be a metabolite of the key fenugreek odorant sotolon.

      So, while this it's still an unanswered question whether improfane's profane stench comes from sweating out his curry obsession, it's sort of a moot point.

      I obviously wasn't clear in my original post, because my point I was trying to make is that many people think that human sweat glands are part of a detoxifying system that removes poisons from the body. It isn't, and it doesn't. This holds true for the OP's suggestion that food smells coming out in human sweat might be related to a similar mechanism in rats, which don't even sweat.

      However, I will withdraw my overly broad statement about where peoples' smells come from because it is possible that some such odors might originate from one's diet. I may have been only partly right on that count.

    35. Re:How did this evolve? by Hognoxious · · Score: 1

      If I stand next to someone long enough, it gives them a disadvantage ;-)

      --
      Confucius say, "Find worm in apple - bad. Find half a worm - worse."
    36. Re:How did this evolve? by rubycodez · · Score: 1

      I often eat food with all that good stuff in it, was wondering if upping the dose would have certain pheronome-like effects, even if only on women from certain parts of the world.

      hmmmm, but not to smell like dinner in places where cannibalism was recently given up.....

  4. It's a shame... by NecroPuppy · · Score: 1

    That the rat isn't from Sumatra.

    --
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    1. Re:It's a shame... by Opyros · · Score: 1

      If it were, the world would not yet be ready for the tale.

  5. Coat by thelowedown · · Score: 1

    Where can I get a Giant African Rat coat before PETA is all over me?

    1. Re:Coat by littlegruz · · Score: 1

      Africa I believe

    2. Re:Coat by omi5cron · · Score: 1

      I'm thinking, if you wear the coat, they WON'T be all over you, except maybe as formerly living activistas!! (yes,that WAS activistas!!)

  6. next thing... by Anonymous Coward · · Score: 1

    he gets a starring role in the desperate A-Team 2: What else can we do to ruin Mr. T

  7. Punk by hoboroadie · · Score: 1

    Another Marvel character, I thought.

    --
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  8. New Pets by Forestwalker · · Score: 1

    Could be a cool pet. Bet no one ever tries to pet it without permission.

  9. Whoa. by blair1q · · Score: 1

    Whoa.

    I dated that chick.

    The 80s were cool...

  10. Pity by ripdajacker · · Score: 3, Funny

    I pity the fool who touches my mohawk!

    1. Re:Pity by funkify · · Score: 1

      Are you calling Mr. T a giant African rat?

  11. Damn by Thinine · · Score: 1

    Damn nature, you scary!

  12. '70s flashback by circletimessquare · · Score: 1

    Ratvis Bickle: [Ratvis is admiring his crest in the mirror] Huh? Huh?
    [Flexes]
    Ratvis Bickle: Faster than you, fucking son of a... Saw you coming you fucking... shitheel.
    [Crest Stiffens]
    Ratvis Bickle: I'm standing here; you make the move. You make the move. It's your move...
    [Lunges]
    Ratvis Bickle: Don't try it you fuck.
    [Reflexes]
    Ratvis Bickle: You talkin' to me? You talkin' to me? You talkin' to me? Then who the hell else are you talking... you talking to me? Well I'm the only one here. Who the fuck do you think you're talking to? Oh yeah? OK.
    [Stabs the wall with his crest]

    --
    intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
  13. Rat poison by shugah · · Score: 1

    So would rat poison (coumadin / warfarin) still work on these rats?

    --
    If you aren't part of the solution, then there is good money to be made prolonging the problem
  14. Re:O'Reilly by Sulphur · · Score: 1

    Okay guys, what book are you gonna put this on the cover of?

    Introduction to Ratfor?

  15. This rat would by future+assassin · · Score: 1

    make quite the politician.

    --
    by TheSpoom (715771) Uncaring Linux user here. I have nothing to add to this but please continue. *munches popcorn*
  16. hedgehogs do it as well by SuperBanana · · Score: 2
    My friend's hedgehog licked my hands and then started foaming at the mouth, and then spreading it on its quills. She explained:

    https://encrypted.google.com/search?q=self-annoiting

    If a hedgehog tastes something nasty, the froth it up and spread it on their spines. It works - if you get pricked hard, you can see a bit of an allergic reaction around the pricks (the spines are not like porcupines, ie, they don't have barbs. They're just somewhat sharp.)

    How can they evolve that knowledge? Or is it aggression that is evolved too?

    The same way any other trait evolves- the ones that do it survive better than the ones that don't.

    --
    Please help metamoderate.
  17. Re:O'Reilly by Alex+Belits · · Score: 1

    Managing Samba4.

    --
    Contrary to the popular belief, there indeed is no God.
  18. Chew by immakiku · · Score: 1

    Summary is a bit inaccurate, leading to uninformed comments and questions on this thread. From the article,

    The researchers found that the rats chew the bark of the poisonous tree and lick themselves to store their poisonous spit in specially adapted hairs.

    They do not eat the plants. They chew it. This is the same way people chew certain herbs and then apply it to wounds to numb the pain. They don't eat those plants - if they did they'd be in poor health indeed.

  19. It's an acquired Immunity! by DadLeopard · · Score: 1

    http://en.wikipedia.org/wiki/Mithridatism It probably starts with the Mother rats milk and continues with additional doses each time it chews the bark! As for the Adaption of the Back hairs, that probably happened when the Rats that had hair better able to absorb the saliva lived longer to have more descendents than the ones that got eaten early because their hair didn't hold enough poison to deter predators!