Cats cannot taste sweet flavors because they lack a functional sweet taste receptor. This is due to a genetic mutation that breaks one of the genes needed to produce the sweet taste receptor protein. As obligate carnivores, cats' systems are not designed to process carbohydrates or sugar, so they have evolved without the ability to taste sweetness. While cats may lick or eat sweet foods like ice cream or marshmallows, they are likely sensing other aspects such as fat, salt, or texture rather than the actual sweet taste. This inability to taste sweet flavors may help protect cats from seeking out carbohydrate-rich foods that are not healthy for them. Thus, cats do not have a sweet tooth like humans or many other mammals do.