Do you have any clothes made out of silk? Perhaps a shirt or a scarf? Some kids may even have bed sheets made of silk. Even if you don’t have any silk clothes, you’ve probably felt the smooth, luxurious fabric at one time or another.

Silk is a natural protein fiber that can be woven into fabrics. Most silk used for clothing comes from silkworms or moth caterpillars, whose larvae produce silk to form cocoons. Many other types of insects, including spiders, also produce silk.

If you’ve ever seen silk up close, you know that it shimmers. This is due to the prism-like triangular structure of silk fibers. These fibers refract light at different angles, producing different colors and the shimmering appearance of silk fabric.

As beautiful as silk is, would you believe that one of its most interesting qualities is its strength? It’s true! As strange as it may sound, silk produced by insects can be stronger than steel.

If you think about it a bit, though, it will make more sense. You know that spiders spin webs. What are those webs made of? That’s right! Spiders spin silk spider webs.

What do those webs do? They catch prey. Spider webs are so strong that they can even catch bats and small birds in flight!

Pound for pound, spider silk is stronger than steel. Plus, it’s lightweight and very flexible. Scientists believe that it could one day be used to make all sorts of advanced products, from replacements for steel cables to lightweight body armor for soldiers.

Today’s body armor used by soldiers can be quite heavy. It’s also not very flexible. Flexible, lightweight body armor made from spider silk could make a soldier’s job much easier and more comfortable.

Unfortunately, spider silk is not easy to make. Just ask a spider! While silkworms can be farmed to produce large amounts of silk for fabrics, spiders don’t tend to play well with each other and can’t be farmed in the same way.

However, silkworms may play an important role in turning spider silk into flexible, lightweight body armor one day. Scientists believe they can now genetically modify silkworms to produce a new type of silk that’s a mixture of worm and spider silk that’s still as strong as pure spider silk. If they succeed, there’s no telling what kind of applications this new super-strong, yet flexible silk could have!

107 Join the Discussion

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    • Thanks for telling us all about your favorite parts of today’s smooth Wonder, Evan! We are really excited to hear about what you learned, too! We are going to pay special attention to the things around us– perhaps the carpets and pillows around us are made of silk! We can’t wait to find out what tomorrow’s Wonder will be– and we LOVE your guesses! :)

  1. Thought: I didn’t know that the cocoon was made with one string. (Shalize) I liked how the silk expert used the machine to wrap the silk. (Maria) I was interested to see how he made the silk. (Toby)

    Connections: This reminds me of the amazing spiderman. (Cristian) This reminds me of when I saw a spider trap another spider in its web. (Pedro) This reminds me of finding three spiders trapped together in a web. (Michelle)

    Predictions: When did gold, silver, and bronze come to be in the Olympics? (Jake) Why do people in the movies win awards? (Cristian) What are the grammy’s? (Andrew)

    • WOOHOO, our Wonder Friends in Mrs. Hess’ Class are here! Thanks for featuring awesome ideas and thoughts from Shalize, Maria, Toby, Christian (are there two of you?!), Pedro, Michelle, Jake and Andrew! It sounds like your class has been discussing lots of different silk products, how silk is made, and connections to today’s Wonder! We thought of Spiderman, too!

      We look forward to WONDERing with you tomorrow, and thank you for sharing your SUPER guesses! We have an award-winning Wonder to share in the meantime: Wonder #663– Does the Olympic Flame Ever Go Out? :)

    • We’re glad to hear it, Ms. Bayko’s Class! Silk is an amazing thing– and it’s used in so much! We enjoyed the video, since we saw exactly how silk is made today! Thanks for telling us about what you learned, and what your guess is for tomorrow’s Wonder of the Day®! We Wonder which Gabby you are referring to… Gabby Douglas from the Olympics, perhaps? :)

    • We agree with you, ThePieGuy23, silk is a heavy-duty kind of fiber! We Wonder if you can think of any other fiber that is strong, like silk? We look forward to WONDERing with you tomorrow, Wonder Friend! Thanks for visiting us today! :)

    • Thanks for sharing your awesome Wonder guess, Alexis! We can’t wait to see what it will be, but we look forward to WONDERing with you again! :)

  2. Dear Wonderopolis,
    Wow! You have given us a lot to think about. We are already planning different designs for body armor. We are also brainstorming other uses for the spider silk, like a hiking trail bridge, hats for construction workers, firemen, policemen, sports players, and bike riders.
    Thank you for inspiration.
    Mrs. Bowes’s Class

    • We’re so happy to know that you’re WONDERing with us today, Mrs. Bowes’ Class! It sounds like you all learned something new with us, including the true strength of silk!! Thanks for sharing all your awesome ideas for ways to use silk– we think a bridge of silk would be WONDERful! HOORAY for you, Wonder Friends! :)

    • Thanks for sharing your favorite part of today’s Wonder, Max!! We’re glad you learned something new about the strength and the process of making silk! :)

    • Hey there, Wonder Friend Alicia, we’re glad to hear what you learned from today’s strong Wonder! You’re right, silk worms look a lot different than we imagined, too! We are so glad you’re here today- thanks for visiting us! :)

  3. Silk is incredibly strong. Its numerous uses is amazing. Scientists belive that they can produce armor for soldiers from silk. This will put the U.S. soldiers at a great advantage because they will have lighter protective gear. The soldiers will have the ability to be more agile and flexible, making them a force to be reckoned with. We had no idea that silk could be used for more than designer clothes and fancy sheets!

    • WOW, we are so happy to see all the WONDERing and ideas that Kemp’s Class has created today! WOOHOO for our Wonder Friends today! We think it’s super cool that you’ve been thinking of alternate uses for silk, especially ways to make protective gear more flexible and efficient! We are sending your virtual high fives for your awesome work today! :)

    • Hey there, Alexa, great guesses for tomorrow’s Wonder! We are glad you enjoyed learning about silk and its different uses today! We can’t wait to Wonder with you again! :)

  4. Today’s wonder was awesome. I liked the video. The silk looked silky and smooth. I think tomorrow’s wonder will be about the Stanley Cup. I love wonderoplis, and I think you should do a wonder about the NHL or about Sidney Crosby.

  5. Today’s wonder was silky. It was awesome. I think tommorrow’s wonder will be about the Stanley Cup. I think wonderopolis is awesome. I wonder if silk can hold 5 pounds? I would like you to do a wonder about Gretzky.

  6. I think the way silk is smooth, soft and mostly comes from silkworms or moth caterpillars is pretty cool. I think tomorrow’s wonder of the day will be about someone famous winning an award or an award show.

    • Hey there, Karsen, we’re glad you liked WONDERing about silk worms with us today! It’s impressive to learn that such strong silk comes from those tiny creatures! We have more respect for spiders and their webs now! Thanks for sharing your cool guess with us, we can’t wait for tomorrow’s Wonder! :)

    • You’re not alone, Wonder Friend Maddy! Fellow Wonder Friend Alicia mentioned the same thing about silk worms! Thanks for WONDERing with us today to learn how strong silk really is! :)

    • Great guess, Liam! We think you and some other Wonder Friends are on the same page! Stanley Cup is one of the most popular Wonder guesses today! We look forward to WONDERing with you again, Liam! :)

  7. Dear Wonderopolis,
    Today’s wonder was awesome!! I wonder if silk could hold 5 pounds? I think tomorrow’s wonder will be about the road to the Stanley Cup.Thanks Wonderopolis!!!

    • It looks like you and Jakob are thinking the same thing today, Ben! We are so happy you’re here today and you’re thinking of the next Wonder, too! We hope you will do some more WONDERing of your own about how much weight silk can hold… perhaps you can conduct an experiment! :)

  8. I think today’s wonder was silktastic! In real life I like silkworms and I think they’re fabulous. I THINK TOMORROW’S WONDER IS THE STANLEY CUP! :)

    • We like your creative, silky work, Jayden! We are so happy today’s Wonder made you smile! Thanks for sharing your awesome Wonder guess for tomorrow– it’s going to be a Wonder goal for sure! :)

  9. HI!

    I liked today’s wonder silk is cool. I never knew that spider silk is as strong as steel and people used it for armour. Surprisingly, bats and birds will get caught in the spider web in flight.

    • WOW, you learned a new thing or two today, Brady, nice work! :)

      We are very impressed with silk’s strength, too, especially since it comes from such a small insect! Thanks for sharing your comment today; we look forward to WONDERing with you soon! :)

  10. Dear Wonderopolis,

    We were surprised to learn that silk is as strong as steel. We also didn’t know that the silk from silk worms comes from their cocoon. We are doing Multiplication Along the Silk Road in our math groups. We learned that the Chinese have multiplication tables that are similar to ours in America. We are WONDERING what happens to the larvae inside the cocoons. Do you know?

    Mrs. Johnson’s class
    Hilliard, Ohio

    • Hey there, Wonder Friends in Mrs. Johnson’s 4th Grade! We’re so glad today’s Wonder is related to your math group lessons! What an awesome connection! It sounds like you’re WONDERing about numbers and different cultures! Thanks for sharing your comment with us! We think your question about what happens inside a cocoon is a great one! We hope you’ll Wonder about cocoons on your own– we’d love to hear about what you find!

      Here’s another Wonder that focuses on the very beginning of an animal’s life: Wonder #834– What is a Tadpole? :)

  11. Dear Wonderopolis,
    I think it’s really cool that silk can hold up to five pounds. Silk is natural protein fiber that can be woven into fabrics.

    • Thanks for summarizing what you learned today, Wonder Friend Nick! Way to go! We Wonder if you have a guess for tomorrow’s Wonder? :)

  12. We think tomorrow’s wonder is about trophies, and awards. We learned that silk is stronger than steel. We learned spiders web is made out of silk.

  13. Thank you Wonderopolis for another interesting wonder. We learned about the life cycle of a butterfly this year and we know that they form their cocoons with silk. Does this mean that the silk made from a caterpillar is the same as the silk made from a spider? We were just curious. Thank you and we look forward to tomorrows wonder.

    • Thank you for visiting us today, Mrs. Kahler’s 2nd Grade Class! We are so glad you could connect your butterfly lesson to our Wonder today! To the human eye, the silk of a worm and the silk of a spider might look the same, but there are some differences. We just read an article about a cross between silk from a worm and a spider– it’s super silk! We think it’s cool to Wonder about all the different things that technology can do, just like this Wonder from the past:
      Wonder #710– How Does Technology Change Lives?

      Thanks for sharing your comment! :)

  14. I think today’s wonder was very interesting. I never knew that silk was so strong until today. Could you do a wonder on soccer? I think tomorrow’s wonder will be about the Stanley Cup.

  15. Hi! Today’s wonder was cool! I didn’t know that spider silk is stronger than steel. Once, my family was leaving to go somewhere, and my momma was walking to the car and she didn’t see, but there was a strand of spider silk attached to the car and it was stuck to the picket fence next to it, and she walked into it, and she said that it pulled her back! So that makes a lot of sense that spider silk is stronger than steel. Thank you for today’s wonder! :) ;)

    • Hey Berkleigh, we’re so happy you’re WONDERing with us! We really appreciate when you share your cool stories with us– you always come up with a great connection to the Wonder of the Day®! It sounds like you and your family are always WONDERing! That spider web must have been incredibly strong! Thanks for sharing your mom’s encounter with us… we are so glad to have a great Wonder Friend like you! :)

  16. Hi Wonderopolis
    Do you remember me. I hope so. The video was awesome. The facts gave me a lot of facts. I have actually tried to break silk but it is really strong. I think tomorrow’s wonder of the day will be about athletes.

    • Welcome back, Gurtej! We’re so glad you’re here today for our silk Wonder! We are glad you’ve conducted an experiment of your own with silk– it sure is tough to break! We look forward to WONDERing with you tomorrow; thanks for sharing your athletic guess! :)

  17. What’s up Wonderoplis,
    How’s everything going?I think today’s wonder of the day was great but not awesome. I think I agree with Ashton. Tomorrow’s wonder of the day will be about Sidney Crosby or the NHL. But to add to that I think tomorrows wonder of the will be about celebrities. Anyway if not about hockey then please make a wonder that is about hockey or Canada.
    :) Just kidding.
    Mushkale :P

    • Hey Mushkale, we’re glad you’re here today! It sounds like a lot of our Wonder Friends have hockey on their minds… we can’t wait to find out what the next Wonder will be! We know you commented on our hockey puck Wonder, but we wanted to share it with you again. Thanks for telling us what kind of Wonders you are interested in, too!

      Wonder #745– What Are Hockey Pucks Made Of? :)

  18. Today’s wonder about silk was really cool. If there was silk on buildings you would stick on the walls. We’re those little white ball things, eggs?

    From: Armaan & Isha :) :)

    • We love your creativity, Armaan and Isha! Thanks for imagining what the world would look like if silk was everywhere! We learned that those small white balls (the ones that look like eggs) are actually cocoons! Thanks for WONDERing with us today! :)

  19. Hi our names are Kabir and Kultar. We really like the post you guys did. Also I saw a fact about spider webs can even catch bats and small birds when they are flying. I also heard that a silk is a natural protein, interesting. I love the post because I didn’t know that much about silk. I wonder what tomorrow’s post is going to be. I think it is about awards.

    • Hey there, Kabir and Kultar! We’re so excited that you enjoyed today’s smooth Wonder! Spider webs are incredibly strong in order to catch their prey. We are so glad that you learned all about something new and you’re WONDERing even more now! Thanks for sharing your guess for the next Wonder– we can’t wait to see you both again! :)

    • Hello to our Wonder Friends the Tigers and Tazmanian Devils! WELCOME– we are glad you’re back! Thanks for joining us today as we learn about the cool properties of silk! We Wonder what you would name the super silk mixture… oh wait, you already shared your awesome names! HOW COOL! Thanks for sharing your comment with us, we’re so glad you’re here! :)

    • Hey there, Wonder Friend Opinion Girl 13! We appreciate your comment about today’s Wonder… we know that WONDERing about insects can make your skin crawl, but we’re proud of you for being here today. Those little white round things are actually the cocoons– that’s where the silk comes from! We hope you have a SUPER day! :)

  20. I thought the wonder was cool but as just being me I don’t like SPIDERS AND CREEPY CRAWLY THINGS! THEY ARE SOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO GROSS!!!!!!!!!!!!!!!!!!!!!!!!!!!! 8^)

    • Hey there, Ashley96, you are not alone! Some of our Wonder Friends here at Wonderopolis are not fans of insects either! However, we sure hope you enjoyed learning about the silk process! Perhaps you have seen some silk at your house– now you know where it originates! :)

  21. Hey Wonderopolis I think this is really cool but the bug kind of looks like maggots so can you do a article about cats??? That would be awesome can’t wait for next Wonder!

  22. I can’t believe this. Silk is really as strong as steel?! That is insane because I could bend a spider web a lot easier than I can bend a piece of steel.

    • Hey there, Wonder Friend Jacob! We are so glad you’re comparing steel and silk! Silk may not look like or feel like steel, but it can be as strong as steel. For example, if silk is woven or spun (like a spider’s web), it can hold something that weighs a lot. We bet you’ll enjoy another strong Wonder about insects:

      Wonder #836– Do Insects Work Out? :)

  23. I think that this was a cool wonder to learn about because I have always wondered where silk was made from. I’ve always heard that silk was very expensive, now I can make an inference why. :)

    • Great job, Wonder Friend Izzy! We are glad you’re using context clues to infer and come to conclusions! We saw all the hard work that insects, and even people, go to making silk! Because it takes such a long time and lots of effort, silk is more expensive! Thanks for sharing your awesome comment with us! :)

    • We are very impressed to learn all about the strength of silk, too, Wonder Friend! Thanks for joining us today to learn something new and cool! :)

  24. I agree to have mustaches on Friday. Today’s article was so cool. I can’t believe that it is possile that silk is stronger than steel. Wonderopolis do you know how much stronger is silk compared to steel??? :|

    • Hey there, Wonder Friend Mustache13! We’re so glad to hear you enjoyed today’s Wonder– silk sure is strong! We know it’s difficult to believe, but silk and steel are very similar. They may not feel the same, look the same, or work the same, but they have similar properties that make each a very strong material! We Wonder if you can do some research of your own to compare the two materials? :)

  25. Hello, Wonderopolis!

    Wow SILK is strong! We know calcium makes our BONES strong! We thing it’s awesome that spider webs are SO STRONG that they can catch birds and bats in flight! Wouldn’t that be a sight!?

    Thanks for sharing!

    • Hello to our Wonder Friends in Miss Hobson’s Class, thanks for visiting us today! We are so happy that you shared your comment with us today– what a great comparison between calcium (for our bones) and silk (for spiders and worms)! We sure are going to look out for silk, especially since we know how very strong it is in nature! :)

    • Thanks for learning something new with us today, Anna! We’re so glad you stopped by to visit Wonderopolis– silk sure is strong! We hope you have a SUPER day! :)

  26. How strong is silk and why. Silk is made from caterpillars. The caterpillars make cocoons and we use that to make silk how people made the silk. First put them in hot water than they find the string put it on this machine and put it on a stick and color it and after that people use it.

    • Nice work, Daniel, we love your summary of what you learned today at Wonderopolis! You’re right, those moth caterpillars specialize in producing silk! We are so glad you enjoyed learning about the process of making silk– we usually only see the finished product! Thanks for WONDERing with us! :)

  27. Dear Wonderopolis,
    Our class was so surprised that silk is stronger than steel. Spider silk could be used for body armor. Really? Some clothes are made out of silk. It takes a lot of work to make silk. Just ask “Charlotte!”

    Our Wall of Wonders is expanding! We can’t wait to show it to you!

    WONDERopolis is awesome!

    Ms. Uppena’s Third Grade Super Sleuths

    • Well hello, Super Sleuths! We think you ROCK! We love that you made the connection between our silky Wonder and Charlotte, from Charlotte’s Web! Charlotte is an awesome character– we are smiling from your awesome comment today!

      Thanks for sharing what you learned, and keeping us posted on your Wonder Wall, too! We can only imagine how WONDERful it looks! Keep up the great work! :)

  28. Dear Wonderopolis, I liked the movie that I watched it was COOL! Also a little gross. I never knew that silk is STRONG! I tried to get on before it didn’t work. Thanks for sharing those COOL VIDEOS! Bye now!

    • Hey there, Tanyalee! Thanks for WONDERing with us! We are glad you have been learning new things about silk and silk worms… we know that WONDERing about insects can make our skin crawl, but we are glad you’re here today! Thanks for watching our Wonder video and sharing your comment! We hope to see you soon! :)

  29. This wonder connected to what we already know because we knew that spiders create silk and that silk can be used for clothing.
    -T, L, & J

    Silk makes me think of a spider’s web weaved at different areas. More like a rainbow for it’s refractive colors.
    -M, A, A, & C

    This wonder helped us understand that silk is very hard to make & it comes from silk worms. It also can be used for many things. Some examples include: clothes, bedsheets, parachutes & jackets.
    -J, M, R, A

    We think the most important ideas are that they are trying to make stronger silk for use in military uniforms.
    -M, H, A, J

    We felt interested when they put the silk into the boiling water because we thought that they gathered it in a different way.
    -F, Y, P

    Our emotional response to this wonder was that of surprise at how silk was made, especially from a spider’s web.
    -E, S, L

    • WOW, we are so glad all of our Wonder Friends in Mr. Daniels’ Period 2 Class are here! You have all done a WONDERful job of making connections to what you know, what you’ve learned, and what you will continue to Wonder about! We are giving you all virtual high fives for your excellent work today! :)

    • That’s great news, Wonder Friend Jeremiah! We love to hear that this Wonder helped you use your imagination! Keep up the WONDERing, and we hope to see you soon! :)

  30. Dear Wonderopolis,

    I did not know that a bugs silk is stronger than steel. That is amazing!

    Your new friend,

    • Hey there, Wonder Friend Magali! Thanks for joining us today to Wonder about the strength of silk! It’s very impressive! We hope to Wonder again with you soon– have a marvelous day! :)

  31. My brother & sister’s class have silk worms as class pets, and I think silkworms are so cool! Where can you get silkworms? And where do mulberry leaves grow? I’m writing a story, and silkworms are involved. This video was great! :) ;) :p :D XD

    • Hey Beau, that’s super interesting! We bet it was a cool learning experience to raise those worms… we’d like to hear more about it! :)

    • Hey there, PeanutButter238! We are super excited that you’ve been WONDERing with us today! Thanks for sharing your comment, we hope to see you again soon! :)

  32. WOW! knights should totally where silk! they’re not thinking right. oh! by the way, i wanted to ask why do we wonder? please answer. thanks! (=

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Have you ever wondered…

  • How strong is silk?
  • Where does silk come from?
  • What are some modern uses for spider silk?

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Try It Out

Want to learn even more about silk and the creatures that produce it? Explore one or more of the following activities with a friend or family member:

  • How large can spider webs get? Jump online to check out photos of the World’s Biggest, Strongest Spider Webs Found! Can you imagine a spider web big enough to span a river? Wow! We WONDER what that web might catch. What do you think? Which web is most impressive to you? Why?
  • Ready to brainstorm for the future? Now that you know that spider silk is incredible strong and could be used to make body armor, we’re WONDERing what other great ideas you might have for spider silk. Grab a friend or family member and do a little brainstorming. What other products could be made from spider silk? How about mountain climbing ropes? Or maybe fishing nets? Put your brain to work and try to think of other uses for super-strong spider silk. When you’re finished, post your best ideas to Facebook to share with your Wonder Friends. We can’t wait to read what you come up with!
  • Want to learn more about the strength of spider silk? Check out PBS Nova’s video on the Strength of Spider Silk. When you’re finished, challenge yourself to answer the questions at the bottom of the web page.

Still Wondering

Through map-making, research and class discussions, children will gain an understanding of the dynamics of trade in China along the Silk Road in ArtsEdge’s Puppets on the Move: China and the Silk Road lesson.

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