Milk is a white liquid, made inside an animal’s body. It contains lots of nutrients that are important for growing and being healthy, so milk is an important food/drink for babies and young animals. But not all animals can make milk: those that do belong to a group called ‘mammals’.
Human beings (like you and me) are mammals, and human babies drink milk as their only food for the first few months of their lives. My children are amazed to think that they drank milk that I made with my body and they want to know: how do mummies make milk?
So, let’s find out more about how mammals work…!
Mammals are warm-blooded animals that have fur or hair on their bodies, and can make milk to feed to their babies. Mammal babies are cared for by their parents until they can look after themselves – and drinking milk from their mummies helps them to grow and develop healthy bodies. As I explained in Is milk a juice?, milk is made of water, carbohydrates, proteins, fats and minerals, and is a good source of calcium and vitamin D.
Mammals make milk in special body parts called ‘mammary glands’. Human mammary glands are called ‘breasts’ and the milk they produce comes out through small holes (called ‘ducts’) in the nipples.
The production of milk is controlled by a hormone called prolactin, which is released in a mummy’s body when her baby is born. Prolactin tells her body to start making milk to feed to her baby. Another hormone, oxytocin, tells her body to let the milk out through her nipples when her baby is hungry.
And, if you liked this post, you might also be interested to read How do nipples grow into boobies?