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5 Animals With Stinky Defenses

You’re chatting with someone you find bright and attractive when suddenly they lean a little closer and WHAM! You get hit with a whiff of monster breath. Nothing pulls the plug on attraction, even just social attraction, like a bad bouquet.

Plenty of animals will run a mile from a foul stench, too. While camouflage, tough skins, and fierce looks are among animals’ great defenses, these five species know that everyone runs from a big stink. (Also see “Top 5 Animal Defense Tactics.”)


In Stand by Me, Stephen King describes a pie-eating contest that turns into “a complete and total barf-o-rama” when the winner intentionally vomits, moving the crowd to follow suit.

king vulture picture
A king vulture at the Zoo Summit outside Panama City in June. Photograph by Rodrigo Arangua, AFP/Getty Images

Vultures, too, know all about puke power. They are scavengers that feast on the rotting flesh of dead animals, which benefits us by ridding our highways and landscapes of carcasses and the bacteria they might carry. When vultures feel threatened they vomit, and the stink of barfed-on carcass puts off most predators.

What’s more, throwing up allows the vulture to fly away more quickly—and the vomit can sting the aggressor’s eyes and face.

It’s generally effective, except when the predator is more foul than the odor—like us. (See: “Elephant Poachers Poison Hundreds of Vultures to Evade Authorities.”)


In some ways opossums have it easy. In order to fake their own death, they don’t have to fax anyone a death certificate, choose a country to hide in, or look over their hairy shoulders for insurance investigators.

opossum picture
A Virginia opossum snarls. Photograph by Steve Kaufman, Corbis

The critters just lie there with their tongues hanging out, sometimes for hours, effectively convincing potential predators they can find a much fresher meal elsewhere. Even if they keep getting attacked, they won’t move any more than a human statue or the Queen’s palace guard until the threat has passed.

As part of their performance fit for Hollywood, possums feigning death even emit a stench, pooping out “extra green smelly mucus,” according to the Wisconsin Department of Natural Resources.

Who smells an Oscar?


If you’re a bird, you’re among some of the world’s greatest singers, dancers, and show-offs. You have to have something mighty special to stand out in that crowd.

hoatzins picture
Hoatzins on the Rio Napo in the Ecuadorian Amazon. Photograph by Jared Hobbs, All Canada Photos/Getty Images

Hold your nose and meet the hoatzin, a bird with a number of distinctions, not the least of which is that it smells like fresh cow manure. The animal mostly eats leaves, which it digests in its crop, a pouch some birds have high up in their alimentary canal. It’s the only bird known to digest by fermentation, like a cow. This process is what causes its odor and has earned it the nickname the “stink bird.”

Don’t knock it, though. That stink means that even people don’t want to eat the hoatzin.

We give points for cleverness to the Cornell Birdscope website for their entry on this aromatic avian, headlined: Alimentary, My Dear Hoatzin!


Millipedes are tricky. For starters they look wormy, but they’re not even insects—they’re arthropods, more closely related to crabs and spiders. Their name is deceptive, too: Their legs number about 750 (not the thousand you’d guess). Despite their horror movie appearance, they’re leaf eaters that don’t bite people.

millipede picture
A millipede can produce hydrogen cyanide. Photograph by Lisa Moore, Alamy

Millipedes have a number of predators, including lizards, birds, and insects, and one of their defenses is to curl up into a ball (which, ironically, makes them look better, even beautiful — at least, to this human eye). Some, though, also release a noxious defensive spray that can irritate skin, harm eyes, and leave a horrible odor on its assailant.

Paul Marek of the Department of Entomology at Virginia Tech told National Geographic that millipedes have about 30 different chemical secretions, so what you get depends on which type you encounter.

These secretions can include hydrogen cyanide. You might want to watch out for two of the cooler-looking ones: Apheloria virginiensis (which Marek says has a nice odor, like cherry cola) releases cyanide, and Narceus americanus releases benzoquinone that can stain your hands. Just ask our intrepid editor.

“Their defense secretions are really for smaller animals,” so if a bird picks them up they’ll get irritated and put them down. If you pick them up, it’s probably best just to wash your hands.

“They taste nasty,” said Marek, and yes, he tasted one—licked it, to be precise, and found it to be a “spicy, burning taste.”

Thanks to his scientific curiosity, we won’t look for a  millipede recipe book any time soon … not even for Halloween.

Sea Hare

The graceful sea hare is toxic in the first place, so it’s not the most popular dish in the sea food chain. Nonetheless, this type of sea slug has a pretty ingenious smell-related defense that is almost the opposite of its odiferous companions on this list. The sea hare secretes a slimy, purple ink that’s a mix of ink and opaline; a 2010 study showed that the substance makes food less palatable to predators.

sea hare picture
The sea hare releases a slimy ink. Photograph by Chris Harris, National Geographic Your Shot

Researchers noticed that lobsters who got blasted with sea hare ink displayed anxious behaviors like flipping their tails and rubbing their mouth parts. And a 2012 study using spiny lobsters as model predators found that the opaline in sea hare ink blocks the lobster’s chemoreceptors, so it can’t smell potential food.

In other words, the sea hare gives its antagonists the equivalent of a stuffy nose so they don’t know how delicious it smells.

Will we have to go to pun jail if we call this chemo-flage?

Follow Liz Langley on Facebook and Twitter.


  1. Bill Taylor
    May 28, 6:17 pm

    You left out the wolf. Baby wolves when left alone in the den let off a scent like a skunk to protect themselves.

  2. Deirdre
    May 28, 3:42 am

    Hi, i wonder if anyone can help me. I was recently in southern Croatia and I came across a tiny black slug at night near my house that the locals fear cos if u accidently stand on it, it stinks out the whole area for ages afterwards.I would be really grateful if anyone knows what it is, thanks.

  3. Claire
    December 18, 2015, 4:37 am

    You guys missed “caterpillar” .

  4. chocaloy
    las vegas
    May 20, 2014, 9:13 am

    Does anybody knows a surot???

  5. Liz Langley
    December 3, 2013, 10:54 am

    Yes, I did miss skunks – stink bugs, too! A couple of people have commented about that and the reason I chose the animals I did was because I didn’t know so they had this defense – I was surprised to find out about the vultures and then looked for others. I had thought “I’ll put skunks in the introduction because they’re famous for stink defense,” and then I got so interested in the other animals I forgot! But you’re right… they are notorious stinkers. 🙂

  6. Shivangi
    New Delhi, India
    December 2, 2013, 12:25 pm

    Heyy! You guys missed Mr. Skunk. 🙁

  7. Magula FC
    Morogoro, Tz
    October 28, 2013, 9:55 am

    Nice reading, was imagining you would talk about stinky bugs!

  8. Matthew Moyles
    September 24, 2013, 5:21 pm

    Interesting. How did you pick these five? I was expecting to see a skunk…

  9. Thomas Lee
    September 22, 2013, 3:40 am

    Love all your facts on all the featured animals… Could you also includes their scientific names too! 🙂

  10. Vaibhav.M.Aher
    September 21, 2013, 2:53 pm

    iam photographer

  11. Morten
    September 21, 2013, 12:30 am

    I’d throw you in pun jail myself if I weren’t so captured by the article.

  12. herbert dower
    September 20, 2013, 9:25 pm

    one correction of note the millipedes here DO bite and there is no antivenom treatment but thing leave them alone and don’t pick them up

  13. ethen
    September 20, 2013, 9:04 pm

    thats cool

  14. Dorky Doo
    September 20, 2013, 1:43 pm

    that is the weirdest thing i have ever seen except for my friend deli

  15. Poop U. Rine
    September 20, 2013, 1:38 pm

    I think that I should eat this with poop.

  16. ronald smith
    new orlenas ,la
    September 20, 2013, 9:42 am

    I just join and what I see wonderful, I just it.

  17. Joseph
    Sydney, NSW, Australia
    September 20, 2013, 6:19 am

    This was brilliant, it seemed like it was put together by very intelligent people, and it was an entertaining read. Although I just wanted to know why the skunk wasn’t in this list.

  18. Gerson Rafael
    September 19, 2013, 12:17 pm

    Muy buena (y)

  19. L. Priyambodo
    September 19, 2013, 12:06 pm

    Have you heard Rice Bug (Leptocorisa oratorius)? If you sprayed by this bug, the smell in your clothes will stay for days!

  20. carlos
    September 19, 2013, 10:02 am

    guao impresionante