Straw Wrapper Wiggle

When drop water on the wrapper, the water molecules will try to get as close as it can to the surface of the paper. And since water molecules are also attracted to one another, it will drag its friends along. This is called capillary action and is why the water travels along the wrapper. The wrapper wiggles and stretches out as the water moves because as its fibers absorb water they swell and straighten out.