What happens when you drop a phospholipid in water?

When a drop of phospholipid is dropped in water, it spontaneously forms a structure called a micelle. A micelle is a lipid molecule that arranges itself in a spherical formation in an aqueous solution, with its hydrophilic head oriented toward the water.  

The formation of a micelle is due to the amphipathic nature of fatty acids, which have both hydrophilic and hydrophobic regions.