As I have explained before, water molecules due to their atomic makeup have one end with a partial negative charge (where the oxygen atom is) and another end with a partial positive charge (where the hydrogen atoms are). This gives rise to a phenomenon called surface tension where water molecules stick to each other (positive to negative) and to surfaces. This effect can be seen in the video below when I poured milk into my coffee before breakfast. The milk, which is more than 90% water, stuck to the side of the glass, and even thought I was tilting the glass more than 80 degrees, not a single drop of milk fell outside!
In case you are wondering, as in my previous Science Before Breakfast video, I had scrambled eggs with bacon and home fries for breakfast but no blueberry toast this time.