A micelle is a roughly spherical group of large molecules that come together in a colloid. For example, a molecule of soap or detergent has a hydrophilic ("water-loving") polar head and a long hydrophobic ("water-hating") nonpolar tail. When soaps or detergents dissolve in water, the molecules clump together to form micelles with the nonpolar tails at the center, surrounded by a sphere of polar heads linked to water molecules. Bile salt in the intestine make the product of fat digestion form micelles, which are thereby more easily absorbed.