 |
Why don't worms have legs? |
by Mya Kagan (whyzz writer) >> more about the author
Squirmy wormy! – Because worms don’t have legs, you probably know them as critters who “inch” or “squirm,” instead of “walking” or “galloping” or “running”.
The reason why worms don’t have legs is that they don’t need them! A worm’s most important job is tunneling around in the earth to help bring water and air to the soil and the roots of plants. For a job like that, legs would probably just get in the way!
Since they don’t have legs, most worms get around instead thanks to the very strong muscles they have which help them to contract and expand their bodies. They simply extend the top portion of their bodies and then bring the back half up to meet it! Certain worms also get some help gripping to the sides of their tunnels because they also have tiny bristle-like hairs on the bottoms of their bodies known as “setae.”
You might think worms are gooey and gross, or you might think worms are gooey and cool! Either way about it, worms are pretty helpful!
Squirm like a worm!
Have you ever tried to squirm like a worm??
Ask a grown-up if there is a clean place on the floor where you can practice moving around like a worm. You might think about putting down a clean sheet or a towel to avoid getting dirty.
Now try moving like a worm! – Without using your hands or legs, extend the front half of your body and then bring the back half up to meet it! Do this again a few times and then check how far you’ve come!
Is it easier or more difficult than you’d imagine to move like a worm? Do you think it would be helpful to have little setae bristles on your underside? What about some special muscles made for this type of movement??
