Why does sweetening milk need less sugar as compared to tea? If I have a cup of milk and a cup of tea; to get them to a sweetness I like, I usually add less sugar to the milk as compared to the tea.

Why is it that milk needs less sugar to be just as sweet as tea?
It's all in your taste buds. Lactose in milk is a form of sugar. It is naturally a little sweet. Tea is slightly bitter so it might seem you need to add more sugar to make it sweet.