This movement is called capillary action . You may recognize the word capillary as a word that refers to tiny blood vessels in our bodies. Capillary actually means any long, thin tube. Your paper towel has spaces that form tubes as well. You can observe the water traveling upwards.
Sponges absorb water by capillary action, as do many kinds of natural fibers used for clothing.
Try Paint with Water . Next time you water a very dry plant, watch drooping leaves spring back to life as water travels from the roots by capillary action. Once you figure out how this is possible, you can do the activity below. See our Bubble Challenge and Paint with Water for more about the amazing properties of water. Water Recipes .