How Come Mammals Are The Only Animals That Produce Milk?

Answer to your only relevant question: Mammals produce milk because they have mammary glands.

 

You ever raise animals that lay eggs? Or walk up on an animal laying on her nest of eggs? They are far from forgetting about them...

 

God made it so.

 

The bigger picture here is that they’re classified as mammals because they produce milk. That encompasses all different kinds of animals lumped into one group with a common trait. That’s like asking why do only birds have feathers?

 

Milk production is another miraculous part of anatomy. I took a course in Lactation when I was an undergraduate in Dairy Science about 45 years ago.

 

Joey, I grew up as a farm kid and many of the things even adults find shocking and intriguing, no longer surprises me. Milk is the lifeblood of survival to all warm blooded creatures, including ourselves. Still I hear "kids" being surprised as to how milk gets on to grocery shelves. I wonder how many people know that a cow simply doesn't produce milk her entire life and the rigors involved in dairy farms maintaining production. It's truly sad that there are so many "educated" people out there without a friggin clue.

 

Because Mammal Evolution works very well!

 

Just like college students who think meat is manufactured at the grocery store.

 

In a different form/process of production, certain birds feed their young a "milk". https://www.worldatlas.com/articles/what-is-pigeon-milk-do-birds-produce-milk.html

Other weirdness in the animal kingdom .. http://www.bbc.com/earth/story/20151016-five-animals-you-never-knew-make-milk-for-their-babies

Regardless, mammals are the only animals that produce "true" milk from mammary glands. That is one of the criteria to belong to the mammals group.

 

And then you have an echidna and platypus who lay eggs and produces milk.....

 

Almonds produce milk..soybeans too

 

And the platypus lays eggs but is a mammal.... and pigeons
feed milk to young and they are birds... sharks live birth but dont feed milk... turtles lay eggs but dont set on them.... hornbills lay eggs then seal off the nest hole and set on eggs until they hatch.... cowbirds lay eggs in other birds nests so dont raise any of thier own young....."Mammary" glands ....

 

Definition of mammal. : any of a class (Mammalia) of warm-blooded higher vertebrates (such as placentals, marsupials, or monotremes) that nourish their young with milk secreted by mammary glands, have the skin usually more or less covered with hair, and include humans.

 

Birds have Breasts but don’t produce milk

 

So do you have breasts that don't produce milk.
Some male babies have Witch's milk yum

 

Nope I have pecs.

 

Nice ones too