Cats

Unlike other mammals, cats lack the proper genetic coding to experience sweet tastes. Cats have a mutant chemoreceptor in their taste buds that prevents them from tasting sweet things, which is actually a trait shared by all cats big and small, not just domestic ones. In 2005, scientists from the Monell Chemical Senses Center, in Philadelphia, discovered that a genetic deficiency deletes the sugar detectors on the taste buds of a cat. In other words, cats do not possess the genetic “hardware” needed to taste sweets.