Why do sweets make people salivate at the thought of them

Picture warm, gooey cookies,crunchy candies, velvety cakes,waffle cones piled high with ice cream.Is your mouth watering?Are you craving dessert?Why?What happens in the brain that makes sugary foods so hard to resist?Sugar is a general term used to describe a class of molecules called carbohydrates,and it's found in a wide variety of food and drink.