What is a Mammal?

Mammals are a group of animals with many traits that make them different from other animals. We have laid out the main characteristics of being mammal. 

  • Endothermic (or “warm blooded”) which means they have a set body temperature.
  • Have fur or hair
  • Give birth to their babies alive, as opposed to laying eggs like fish or birds.
  • Lactation (being able to make milk to feed their babies)

There are many animals that are still mammals, but don't exhibit all these traits. Here is some mammals that don't meet every requirement. 

  • Dolphins (don’t have fur)
  • Platypus (lays eggs)
  • The Naked Mole rat (is exothermic, or “cold blooded”)

Mammals are the only animals in the world that can make milk. Being able to lactate is the one true qualification to being a mammal.


Mammals come in all shapes and sizes, some mammals are some of the largest animals on the earth. Here is brief list of some giant mammals. 

Mammals are also very small. Check out this small list, on small mammals:

  • Bumblebee bat
  • Pygmy shrew
  • African pygmy mouse

Mammals are a diverse group of animals that include the majority of animals we see and talk about daily. 

Check out all the mammals and other animals in the Kids Zone.  You can do mammal coloring pages, read blogs on mammals and even quiz yourself on everything you learned.  Check it defenders and be sure to teach someone else about animals!

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