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World’s Biggest Spider Explained

In a world where even the smallest spiders can provoke a fearful shriek, Theraphosa blondi takes scare tactics to a whole new level.

This South American tarantula holds the record for world’s largest spider. Other spiders might have longer legs, but T. blondi‘s large body means its overall weight can reach 6 ounces (170 grams).

Commonly known as the Goliath birdeater due to an 18th-century engraving showing another member of the tarantula family eating a hummingbird—which gave the entire Theraphosa genus the nickname of “bird eaters”—the gargantuan spider is not quite as menacing as it might seem.

Despite its nickname, T. blondi only rarely devours birds, notes the Encyclopedia of Life. According to spider expert Gustavo Hormiga at George Washington University, T. blondi mostly eats arthropods.

“They are general predators, and if they run into other vertebrates like a small mouse or lizard, they can eat those, too,” Hormiga says.

But don’t expect this Goliath to use a giant web to snare its prey—T. blondi hunts for its meals the old-fashioned way, using its large fangs to bite and kill. (Watch video: “How to Survive a Giant Tarantula Encounter.“)

Like most spiders, T. blondi produces venom, although Hormiga notes that it’s not particularly toxic to humans. The bites have been described as feeling like wasp stings, but they almost never require medical attention.

Beware the Hair

Although T. blondi doesn’t weave a web, it does produce and use silk. The spider lives in burrows beneath the forest floor, which it lines with silk to give the structure more stability. Should a mammal try and dig up the burrow for a tasty spider snack, T. blondi has a weapon more useful than venom: urticating hairs on its abdomen. (The technical term is bristles, as only mammals have hair, but even scientists use the more popular term in conversation.)

“These are shaped like little harpoons if you look at them under the microscope,” Hormiga says, which gives the hairs the ability to embed in the skin.

“These spiders very quickly rub their fourth pair of legs on their abdomen to release the hairs, which then become airborne. These are very itchy.” (Related: “Tarantulas Shoot Silk From Feet, Spider-Man Style.”)

The urticating hairs don’t need to be airborne to do their damage, however—researchers and owners of pet spiders need to handle the Goliath birdeaters with gloves. To large animals like humans, the hairs are merely irritating and itchy, but they can be fatal to smaller mammals like mice.

T. blondi females lay between 50 and 150 eggs in a giant sac that can measure over an inch (30 millimeters) in diameter. They cover the sac in urticating hairs to keep predators away.

It takes about two to three years for these hatchlings to mature; they spend significant amounts of time living with their mother in her burrow until they get old enough to fend for themselves. Although females can live up to 20 years, males have a life-span of only 3 to 6 years, often dying soon after reaching maturity and mating.

Tastes Like Prawns?

Many of the locals in northeastern South America regard T. blondi as a tasty snack. They first singe off the urticating hairs, then wrap the spider in banana leaves to roast. Tarantula expert Rick West, who once sat down for a meal of these spiders with the local Piaroa peoples of Amazonas in Venezuela, says T. blondi can be surprisingly tasty and moist. (Also see “U.N. Urges Eating Insects; 8 Popular Bugs to Try.”)

“The white muscle ‘meat’ tastes like smoky prawns, while the gooey abdominal contents is hard-boiled in a rolled leaf and tastes gritty and bitter,” West says. “The three-quarter-inch (two-centimeter) fangs are used after the meal as toothpicks to remove T. blondi exocuticle from between one’s teeth.”

It’s not often that your dinner comes with built-in toothpicks. Despite its shrimp-like taste, however, you probably won’t see Goliath birdeater on a restaurant menu any time soon.

Follow Carrie Arnold on Twitter and Google+.

giant spider screengrab


  1. Carlos
    April 28, 2014, 4:02 am

    This is NOT the worlds biggest spider! Do your research before claiming such!

  2. stuart longhorn
    United Kingdom
    November 5, 2013, 12:09 pm

    So, as others have said, why please is the spider used in the video and static image Theraphosa stirmi (from Guyana) and not the focal species of the article Theraphosa blondi (French Guyana/Suriname)? If you are going to talk about a certain species, it is potentially misleading to then show another, which can have a variety of different attributes. I expect the wrong images to be used in poor news reports but not National Geographic.

    • Carrie Arnold
      November 5, 2013, 3:13 pm

      Stuart, I’m honestly not sure. I wasn’t in charge of the video for this post- I will ask and get back to you. Thank you for pointing this out. –Carrie

    • Christine Dell'Amore
      November 6, 2013, 3:50 pm

      Thanks for the comment Stuart — I’m the editor of this blog. We added a line under the video to clarify that the species of tarantula in the video are not T. blondi. I agree with you that ideally it would have been better to have a video solely focused on T. blondi.

  3. danish turk khan
    baramulla,kashmir india
    November 4, 2013, 3:17 am

    i am to workiong on white widow having dfferent and 8 different species from last 7 year

  4. Eric Simpson
    November 3, 2013, 1:37 am

    Carrie Arnold, why did you agree to Laura of Florida’s comment about tarantulas not being spiders? Tarantulas are within the Order Araneae, and are therefore spiders.

    • Carrie Arnold
      November 5, 2013, 3:12 pm

      I think we read the comment differently. I was agreeing that T. blondi was a tarantula–which it is. It’s also a spider.

  5. dlut414
    November 2, 2013, 12:51 pm

    considering getting one as pet

  6. Benjamin T.A
    Nigeria, Africa
    November 2, 2013, 10:12 am

    Wow the tarantula is really a big and scary kind of spider, but is there any big spiders in Africa?

  7. Doc_Anchovy
    Eureka, CA
    November 2, 2013, 6:09 am

    Love all the multiple punctuation marks in this “scientific” comments area.

  8. Francisco José R. Prestes
    Manaus, AM, Brasil
    November 2, 2013, 1:51 am

    A Theraphosa blondi é uma aranha da ordem araneae, subordem Opistothelae, infraordem mygalomorphae, família theraphosidae e subfamília theraphosinae. E a aranha do vídeo não é a espécie “blondi” e sim a “stirmi”, ou seja, Theraphosa stirmi que também alcança um tamanho gigantesco. Muito encontrada na região amazônica brasileira.

  9. aida cadena
    United States
    November 2, 2013, 12:47 am

    I’m terrified and fascinated….but more terrified.

    • Carrie Arnold
      November 2, 2013, 9:58 am

      I totally understand your sentiment!

  10. Stephanie Wallace
    Long Beach
    November 1, 2013, 5:50 pm

    Thank you for the information, these are amazingly beautiful tarantulas, I hope to see one in its native habitat one day.

    • Carrie Arnold
      November 2, 2013, 9:58 am

      Good luck on your search! Maybe one day I’ll be brave enough to go seek one out. 🙂

  11. Stephanie Wallace
    November 1, 2013, 5:48 pm

    Beautiful tarantula. I have a few as pets but yet to add the bird eater,what a magnificent creature. :).

  12. Raquel
    November 1, 2013, 11:52 am

    A tarantula is a type of spider, therefore ALL tarantulas are spiders.

  13. Laura
    November 1, 2013, 10:02 am

    Someone please tell National Geographic that a T blondi is NOT a spider but a tarantula. There is a difference between the 2 so why, why can’t you get it right!!!

    • Carrie Arnold
      November 1, 2013, 11:30 am

      Good point. I did try to mention early on that T. blondi was a tarantula, however!

  14. dare
    November 1, 2013, 9:19 am

    Looks just like my baby, Gilly. I have one. Beautiful creature.

    • Carrie Arnold
      November 1, 2013, 11:30 am

      I’m glad you like these amazing creatures. 🙂

  15. Ito fernando
    November 1, 2013, 3:51 am

    Tasty?? Eeeww..

  16. caroline keter
    eldoret kenya
    November 1, 2013, 12:48 am

    Now that’s something i didn’t know that i now do. Great article. Interesting read.

  17. Leo
    October 31, 2013, 9:13 pm

    The last name of the spider expert is HORMIGA(ANT)?????? Are you kidding me?

  18. wayne
    October 31, 2013, 7:23 pm

    Good one, you didn’t even bother to say or clearly show how big it is

    • Carrie Arnold
      November 1, 2013, 11:28 am

      The second paragraph says that they can weigh around 6 ounces. I looked up the legspan for you, and it’s about a foot across.

  19. Carol Carter
    United States
    October 31, 2013, 4:33 pm

    Eeeewww!…That’s such a big, disgusting spider!…..Everything is supersized down there!…..I would not make a good dinner guest with the indigenous tribes…..

    • Carrie Arnold
      October 31, 2013, 4:37 pm

      I can’t say I would have taken a bite, either–although I think it’s good to step outside our comfort zones once in a while!

  20. Bart
    October 31, 2013, 3:34 pm

    Update Flash?! Really! It’s 2013. 🙁

  21. km
    October 31, 2013, 9:12 am

    yeesh..lol..eww..and all the other words we use when we run across a reg spider, never mind that one..I know folks have em as pets, and I was reading about the molting process which is fascinating..great article..