Are Crocodiles Mammals?

All creatures in the animal kingdom, from dogs and flamingos to whales and clownfish – and even you, are divided into groups for classification. These groups are mammals, birds, reptiles, amphibians, fish, invertebrates, and insects.  

Are crocodiles mammals? Crocodiles are not mammals, but instead, they are reptiles. Let’s take a look at why crocodiles are considered reptiles. Remember what makes an animal a reptile: they must be vertebrates, cold-blooded, covered in scales or plates, and lay eggs. Crocodiles have a backbone, making them vertebrates. Crocodiles are also cold-blooded. Cold-blooded animals cannot regulate their body temperature internally, which makes their temperature variable in their environment.

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Crocodiles will bask in the sun to get warm and will go in the shade if they want to cool down. Crocodiles are also covered in boney scales called scutes. These scales protect crocodiles from losing water from their bodies. Female crocodiles also lay eggs two months after mating. Crocodiles will dig a hole to make a nest near a riverbank, shoreline, or streambed. And get this- females can lay up to 80 eggs at a time!  

Let’s take a closer look at groups of animals and see what animals fit into each group.


Mammals are creatures that have backbones (called vertebrates), have hair on their bodies, are warm-blooded, and feed their young with milk. Mammals also have a more developed brain than other animals. Dogs, cats, elephants, horses, dolphins, whales, monkeys, tigers, and humans, are all mammals.  


Like mammals, birds are also warm-blooded and they are vertebrates. But a big difference between mammals and birds is that birds are the only animals with feathers! Even though all birds have feathers, not all of them can fly. Penguins, flamingos, robins, eagles, owls, peacocks, and ducks are all birds.  


Reptiles are vertebrates like mammals and birds, but they are cold-blooded. The skin of reptiles is covered with scales or plates and they usually lay eggs, instead of giving live birth. Alligators, chameleons, cobras, sea turtles, and rattlesnakes are all reptiles.  

Are Crocodiles Mammals
Are Crocodiles Mammals?


Amphibians are cold-blooded vertebrates like reptiles, but the big difference between amphibians and reptiles is that amphibians do not have scales. All amphibians live partly on land and partly in the water. Poison dart frogs, spotted salamanders, bullfrogs, and toads are all amphibians.  


Fish are vertebrates that live in water. But what makes them different from other animals that live in water like dolphins or sea turtles? Fish breathe underwater by using their gills. Clownfish, great white sharks, pufferfish, seahorses, stingrays, and catfish are all fish.  


Invertebrates are animals that do not have a backbone or a skeleton made of bones. Invertebrates range in size from almost microscopic to giant. Fireflies, giant squids, bumblebees, jellyfish, butterflies, tarantulas, and starfish are all invertebrates.  


Insects are animals that have a hard shell outside of their bodies called an exoskeleton. Most insects have wings and antennae, and all insects have six legs. Ladybugs, beetles, moths, mosquitos, and termites are all insects.  

Where do crocodiles live? 

Crocodiles can be found in many tropical climates and can be found in the tropical areas of Africa, Asia, Australia, and North and South America. Crocodiles live near lakes, rivers, and some crocodiles even live in saltwater areas.  

One of the largest populations of crocodiles can be found in the Dominican Republic. It is here in the DR’s large saltwater lake called the Lago Enriguillo that many American crocodiles live.  

Where do crocs live
The Nile River

What do crocodiles eat? 

Crocodiles like to eat fish, frogs, lizards, insects, crustaceans, and small mammals.  

How old do crocodiles live? 

Crocodiles live a pretty long time! The average lifespan of crocodiles is about 70 to 100 years. But the oldest living crocodile lived to be 140 years! This crocodile was named Mr. Freshie and he lived in Australia. He was caught by the famous “Crocodile Hunter” Steve Irwin. Currently, the oldest living crocodile is a saltwater crocodile named Henry. Henry is 120 years old and he lives in South Africa. Henry has fathered over 10,000 baby alligators over the past 35 years!