Bug of the Week: Silkworms

It has been cold and rainy here this week, but we still have plenty of insects. You see, they are all indoors.

Here is the story of our silkworms in photographs:

We bought our caterpillars over the Internet. They arrived in a plastic cup. Look at all the colors!

The caterpillars ate a commercial food made up of dried mulberry leaves and thickeners. We bought some extra food from the supplier, because we weren’t sure we could find mulberry leaves. We made it in the microwave by mixing the powder with water and cooking it.

After a few weeks, we did find some mulberry leaves.

The caterpillars ate a lot of mulberry leaves.

The caterpillar makes silk with a gland that exits in its mouth.

When they are ready to pupate, the caterpillars start to make a silk bag around themselves, which is the cocoon. The cocoon is what is used to make the fabric silk.

When we did this before, all the cocoons were white. This time they were white, pale yellow and deep golden yellow. (The colors have to do with the mix of varieties we got.)

After about two weeks (depends on the temperature), the first moths emerged.

This is a male. Isn’t he cute?

The females laid eggs on other cocoons and on some cardboard egg cartons we provided.


The eggs are the size of pinheads or slightly larger. They are light to dark gray in color.

The best part of this project has been sharing the caterpillars and the stories with our friends.

For more information about silkworms, see Silkworms: A Thread through History, and also the link at the end of that post.

Related books (with Affiliate links to Amazon)

Silkworm (Life Cycle of a . . .) by Ron Fridell and Patricia Walsh

Age Range: 6 – 8 years
Publisher: Heinemann; 2nd Edition edition (August 15, 2009)
ISBN-10: 1432925458
ISBN-13: 978-1432925451

The Story of Silk: From Worm Spit to Woven Scarves (Traveling Photographer) by Richard Sobol

Age Range: 6 – 9 years
Publisher: Candlewick (September 25, 2012)
ISBN-10: 0763641650
ISBN-13: 978-0763641658




    A little creepy for me….but still, amazing!

    My Wednesday post is all WATER today…the Gulf Water that is. FOUND HERE

  2. Sandra Foyt

    Incredible photos, especially the one showing the worm emitting a silk thread. Can you tell me where you got the silk worms, and their food?

  3. Snowcatcher

    Your photos are indeed incredible. How cool that you are raising moths! Do you use the silk, too?

  4. Roberta

    We got the caterpillars and the silkworm chow from Mulberry Farms http://www.mulberryfarms.com/store/, but there are other places. You might want to search for silkworms in your search engine for a local supplier.

    As for what we do with them, once the moth has emerged from the cocoon, it is difficult to use the silk because the threads are cut short. We are going to see if we can raise another generation and my son has come up with a sweet craft project that uses the cocoons.

  5. caribookscoops

    Wow what a fabulous project. My daughter enjoyed your photos. I have to admit I didn’t tell her we could order her own set of silk worms though. Not sure I could deal with that one.

  6. CreativeKat

    We’ve been raising silk moths in my classroom for over ten years. It’s something I really look forward to. This year, I was recovering from cancer and wasn’t going to do it. But two students whose older brothers had been in my class years before asked if we could. Their siblings had shared the experience with them and they couldn’t wait to try it on their own. I figured if it had that much of an impact on the students that they remembered it years later, we should do it again. The eggs came this week. One batch is going to make pink cocoons!! My mulberry tree source also appreciates the pruning, and are the best looking trees around! I just read another post where the person used to feed her silkworm caterpillars beet leaves, and they would make pink silk. I am going to see if they will actually like beet leaves, for diet variety πŸ™‚ We used to raise several generations, then they would get weak from the inbreeding and I’d order them again. Of course, it’s always tricky if you get too many. These little guys are so cute, I hate to see them go as pet food. Thanks for posting these terrific pictures! Good luck to everyone! (remember to tell the students to wash hands before and after handling, the silkworms are sensitive to germs.)

  7. CreativeKat

    P.S. I ordered from Coastal Silkworms this year, because their prices are good. http://www.coastalsilkworms.com. And I got little individual boxes for the kids at a reptile supply house. http://www.LLLReptile.com for 1.99 each. This way each student can be responsible for his/her own caterpillars.

    I would be interested in the art projects some people say they make from the cocoons once the moths have vacated. Thanks! πŸ™‚

  8. Shirley

    My 5th grade class raised silkworms one year and it was fascinating. A friend gave me some eggs and I was desperate to find mulberry leaves (didn’t know about the mix). I told the kids we had to have them and they got all excited. Two “berry trees,” as they called them, grew next door to the school. Every day I stopped on the way to work to pick fresh leaves which the kids fed the worms. The entire process was a new experience to us all.

    Thanks for the link to this post. It brought back some fun and funny memories. My mom was librarian at the same school. She came in to see the silkworms and asked a student what the worms were doing. the student replied, “They’re mating.” My mom’s eyebrows raised and she left in a hurry. They joys of teaching science.

  9. Serenity Weston

    In my book report book this school year, ( I am in grade 5 ), it talks about silkworms. These little creatures make all the silk we produce. In order to get the silk, though, we have to kill the pupae while it’s in the chrysalis. We have to boil them in hot water, and then make thread by weaving together 5 strands of the silk. Then we make clothe, ect. I finished this book, and wanted to know more about silkworms. I found this website, and I’ve learned a lot more about these cute little creatures. I want to thank everyone who put up this website; it has helped me learn so much more about these silkworms.

  10. Roberta

    Your explanation is good. I would only make one suggestion. The silk wrapping around a moth pupa (a silkworm is a moth) is called a cocoon rather than a chrysalis. The chrysalis is the pupal stage of a butterfly. People often mix those two up, even in books.

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