Many students think that liquids are pulled up a straw due to suction
When students use a straw, they will observe liquid rising and may assume that sucking on the straw is pulling the liquid through. When asked about why the liquid rises, they will often fail to include ideas about pressure in their explanation.
Students are unlikely to correctly explain that sucking on the straw lowers the pressure inside the straw and your mouth to below atmospheric pressure which then pushes the liquid further up the straw.
Resources to Address This
Use this Marvin and Milo activity to get students thinking about why they are unable to drink water with 2 straws in their mouth (one outside the glass).View Resource
With thanks to the teaching community for submitting this misconception.