You may have wondered why it seems that all of your cereal clumps together in the middle of the bowl, even when you only have a few bits left to eat. The fact that cereal accumulates toward the center is due to something scientists have called "The Cheerios Effect." In 2005, the effect was mathematically proven. The surface tension between the milk and the bowl causes the milks surface to cave in slightly toward the middle of the bowl. Similar to the cohesive and adhesive properties of water, these properties in milk cause a concave surface of the milk. Clearly once one understands that the surface of the milk is caved toward the middle of the bowl, it is clear that there is a component of the force of gravity pushing the cheerios together into the middle of the milk's surface as the friction between the milk and the cheerio isn't enough to counteract the component of the force of gravity.