Question

Why does our mouth water when we eat something?

Answer 1

Whenever we eat something our mouth water.It is actually the secretion of saliva by the salivary  glands.Saliva contain some digestive enzyme which helps to break down starch into its simpler form,sugar.It also helps to make the food softer and make it easier for chewing as well as swallowing it.
HOPE IT HELPED!(I'M THAT BAD IN BIOLOGY......BUT STILL....I TRIED!)

Answer 2

its not actually water...........its saliva............this is a digestive juice secreted by the salivary glands....it makes the tiny particles of  food in a soluble form.