Physicist: Surface tension. There are a lot of details and phancy physics behind surface tension, but the main idea behind surface tension comes from what separates liquids from gases. So surface tension is just the liquid trying to have the minimum possible surface area. Insects that walk on water have hydrophobic oils on their feet that don’t mix with water, so the water instead has to move out of the way. “Hydroplaning” here means pushing on the water faster than the water can move out of the way.