What you need
A straw with a paper wrapper, a glass of water, a table
What to do:
1. First you need to get the wrapper off the straw correctly so you can use it. So maybe you can have a couple of standby wrapped straws, if something goes wrong.
2. Hold the straw upright on the table. Pinch the upper end of the wrapper and firmly pull it straight down. The paper should be bunched up the straw.
3. Now place this bunched paper on the table.
4. Dip the straw in the glass of water. Plug the top with your thumb so that some water is pulled into the straw.
5. Without removing your thumb, bring the straw out and hold it over the paper.
6. Lift your thumb partly to release some water and quickly place it back
What happens:
The bunched paper sort of grows out into a worn. You can keep releasing a few drops of water at a time on the worm until it stops growing.
Why?
Capillary action! Capillary action is the movement of a liquid against gravity, through narrow spaces. This is the same principle that allows water to be absorbed by a tree’s roots and transported to its leaves.
Paper contains these narrow spaces or capillaries through which water moves as it is absorbed
When enough water is absorbed, the paper swells and its folds open out to make your worn wriggle happily. Don’t put too much water on it though, or you will be left with a limp, soggy worm.
Picture Credit : Google
