Human milk is sweeter than other mammal milk because it has more sugar, about 21 percent. These sugars though are unlike those in formula as they are similar to those found n the surface of a human cell and are actually formed within the breast with the same exact enzymes. They behave like a decoy that harmful viruses and bacteria then bind to. Not to mention human lactose, that sugar that fuels an infant's brain growth. There is also a sugar that feeds the beneficial gut flora. In other words there is a lot of human sugar found in human milk. I would imagine that formula manufacturers are trying to create a similar sweet taste since humans infants are geared to the taste of sweet breast milk, though unfortunately the sugars in formula are not the same.