In North America, there is a pig whose head and tail are only as big as mice and cats. That's an opossum. The North American opossum is a very old mammal, somewhat similar to the kangaroo and koala we are familiar with. The little opossum is as big as a mouse, and the biggest one is bigger than a cat. This is the most motherly animal in the world. .
Because opossums have no placenta, the way of reproduction is also very old. After the baby is born, the opossum will climb into the mother's pouch to nurse, which is a bit like a kangaroo.
The opossum is pregnant for a short time. Generally, you can give birth to a bunch of bee-sized opossums within one month of pregnancy. Next, as many opossums as this pile need to climb into their mother's bag to eat. But the mother opossum will have 13 nipples for the baby opossum.
So only thirteen opossums in a pile can survive. After the opossum grows up in the pouch, the little opossum will climb on its mother's back and do some actions with its mother, which is also the origin of "opossum". This is why opossum is the most maternal animal.
In nature, some animals love their children as much as humans. Most mammals will protect their children after giving birth until they grow up and face danger independently. Even the cats and dogs at home will protect their children.