Milk, quite simply, is a liquid that mammals can create in mammary glands in order to feed their young. The reason mammals have this is because this is what their young are naturally supposed to consume until they are strong enough or old enough to hunt for themselves or eat what their parents typically eat. Humans also have this ability, which is why we have begun to explore the interesting world of milk from other animals, in the hopes that milk could continue to nourish us throughout our lives, rather than simply at the beginning of it. Spoiler Alert…we were right! Milk can be very beneficial to us at all times of our life!