What is your favorite animal? Some may say a type of bird or cat. Other people are fascinated by fish or snakes. Whatever animal you thought of belongs to a group called the Animal Kingdom. The Animal Kingdom can be divided into two large categories: vertebrates and invertebrates.

Any animal that has a backbone is a vertebrate. There are five groups of vertebrates: amphibians, reptiles, birds, fish, and mammals.

Amphibians can live on both land and in water. They are cold blooded, which means their body's temperature matches that of their surroundings. Amphibians also lay eggs, from which their young hatch. Frogs and salamanders are both types of amphibians.

Reptiles have dry, scaly skin, are cold-blooded, and lay soft-shelled eggs. Reptiles are born on land and with very strong instincts. They are on their own at birth. Just think, no parents to nag them about cleaning their rooms. Some common reptiles are snakes, lizards and turtles.

Look up on a clear day and you will probably see another vertebrate called a bird. Birds are easily recognized by their feathers and wings. Birds also lay eggs but are warm-blooded, which means they can control their body's temperature. Penguins, chickens, and ostriches are all types of birds.

Fish live underwater and use gills to filter oxygen out of the water. They use fins to move, lay eggs, and are cold-blooded. Some types of fish include sharks, eels, and rays.

As humans, we fit into a group of vertebrates called mammals. Mammals give birth to live young, are warm-blooded, have hair or fur, and use lungs to breathe air. Dogs, elephants, and even whales are types of mammals.

Animals that do not have a backbone are called invertebrates. Worms, spiders, snails, and insects are all examples of invertebrates. 97% of all animals are invertebrates.

So, the next time you go for a walk in the woods or a stroll along your favorite beach, keep an eye out. See if you can identify which group each animal you see fits into.

Lexile: 500-600
Words: 337
Genre: Nonfiction, Science
Read time: 2:15
Printable version
Story questions
Read by: Brian James
Illustrations by: Iryna Novytsky