Milk is a white liquid food produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals before they are able to digest solid food. Milk contains proteins, fats, lactose, and various vitamins and minerals. It is consumed by humans as a food source and can be processed into a number of dairy products such as butter and cheese. Within Oceanyka, milk is produced in a roughly 50/50 manner by cows and Eta. The latter's is very similar to goat milk, which is also produced in small quantities.