Why is a penguin considered a mammal?

Penguins are warm blooded, have feathers rather than fur, lay eggs, have wings and the females don't produce milk for their young. They are birds, Subclass Impennes, Family Spheniscidae. read more

Penguins are not mammals. They are birds because their bones are hollow, they have wings and feet instead of legs and paws. They also have feathers instead of hair, beaks instead of mammal facial features, and lay eggs instead of having a live birth. read more

Penguins are not mammals, even though they are warm-blooded animals. Penguins are one of only a few species of flightless birds left in the world. Many people mistakenly believe penguins have fur instead of feathers because of the extremely tight packing of the feathers on their bodies. read more

They are flightless birds. Penguins are often mistaken for mammals or amphibians because they spend a good amount of their lives either on land or swimming in the waters to catch fish. read more