Who feed their baby with own milk?

The most common answer is mammals. Mammals are the only animals that produce milk to feed their young.

Here's why:

* Mammary glands: Mammals have specialized glands called mammary glands that produce milk.

* Nursing: Mothers nurse their offspring, allowing them to suckle the milk directly from the mammary glands.

Of course, there are exceptions:

* Monotremes: These are mammals that lay eggs (e.g., echidnas and platypuses). They don't have nipples, but they do produce milk and feed their young from a patch of skin on their abdomen.

* Adoption: In rare cases, other animals (like birds or dogs) may adopt and raise young that aren't their own. In these cases, the adoptive parent is not biologically related to the young and wouldn't feed them with their own milk.

So, while mammals are the primary answer, it's important to remember that there are some interesting exceptions to this rule!