If the things we make from wool shrink after getting wet, shouldn't the wool shrink while it's still on the sheep's back, too?
There are two main things that help the wool on a sheep's back to not be affected by water the same way as your wool sweaters: One factor is the way the tiny fibers grow on each strand of wool. As a sheep's hair grows out of its back, the fibers of each strand, which are scaly, point out towards the same direction. However, when wool gets woven together into a sweater, all of these strands and their fibers suddenly point into many different directions! When the wool gets wet and then dries, the fibers that point in opposite directions latch on to each other and lock closer together, meaning all the strands of wool pull together tighter than before, and your wool sweater shrinks up! The other factor that helps a sheep to keep his or her coat from shrinking is lanolin, an oily substance produced naturally by sheep. The lanolin keeps the scaly wool fibers slick and helps prevent them from locking together!
Thanks to these helpful things, a fluffy, wool-covered sheep can definitely get wet without having to worry that he or she might shrink up! -- PHEW!!
(by Mya Kagan, Whyzz writer)
Things like wool sweaters are "woven" together. Try this project at home to weave your very own art out of paper!Gather up a few different colors of paper, and cut them into long strips that are each about 1-inch wide. Then, set down one larger piece of paper that will be the back of your project. Pick out five of your paper strips and lay them out on your large piece of paper so that they are in evenly-spaced rows. Use a little piece of tape on the ends of each strip to secure them down onto the larger piece of paper. Now, you're ready to start weaving! Take more of your paper strips, one at a time, and pass them through the strips you've taped down to the paper, alternating the loose strip over then under the ones on the paper! This is what it means to weave two things together!Keep working with each of your strips until your page is full, making sure to switch your over-under pattern with each new strip. When each new strip is finished, tape it down to your paper too.If you use lots of colors, you'll end up with a pretty cool, colorful, woven paper picture all of your own!