Explore the Animal Kingdom: A Kids' Guide to Wildlife

The animal kingdom is one of the most fascinating things on our planet. Scientists have identified over 1.5 million animal species so far, and they estimate there could be millions more we haven't discovered yet. From tiny insects you can barely see to blue whales the size of three school buses, the variety of life on Earth is truly mind-blowing.

Let's take a tour through some of the major animal groups and meet some of the most incredible creatures out there.

Mammals

Mammals are the animal group that includes us. What makes a mammal a mammal? They're warm-blooded, they have hair or fur, and mothers feed their babies milk. There are about 6,400 known species of mammals.

Some of the most remarkable mammals include:

• Blue whales are the largest animals that have ever lived on Earth. They can grow up to 30 meters long and weigh as much as 200 tons. Their hearts are about the size of a small car.
• Cheetahs are the fastest land animals, reaching speeds of up to 120 kilometers per hour. But they can only keep that speed for about 30 seconds before they overheat.
• Elephants have incredible memories and can recognize hundreds of individual elephants. They mourn their dead and have been observed holding "funeral" ceremonies.
• Bats are the only mammals that can truly fly. There are over 1,400 species of bats, and they eat everything from fruit to insects to (in a few rare cases) blood.

Birds

There are about 10,000 species of birds, and they live on every continent, including Antarctica. All birds have feathers, lay eggs, and are warm-blooded. But not all birds can fly.

• Ostriches are the largest living birds. They can't fly, but they can run at speeds up to 70 kilometers per hour, making them the fastest birds on land.
• Hummingbirds are some of the smallest birds in the world. The bee hummingbird weighs less than a penny. They can flap their wings up to 80 times per second and are the only birds that can fly backwards.
• Arctic terns have the longest migration of any animal. They fly from the Arctic to Antarctica and back every year, covering about 70,000 kilometers annually.
• Crows are incredibly intelligent. They can use tools, solve puzzles, and even recognize individual human faces. Some scientists believe they're as smart as a 7-year-old child.

Reptiles

Reptiles have been around for over 300 million years. They're cold-blooded, which means they rely on their environment to regulate their body temperature. There are about 10,000 known species.

• Komodo dragons are the largest living lizards, growing up to 3 meters long. They're powerful predators with venomous bites.
• Chameleons can move their eyes independently, seeing in two directions at once. And yes, they really do change color, though it's more about communication and temperature regulation than camouflage.
• Sea turtles have been around since the time of the dinosaurs. Some species can live over 100 years, and they return to the same beaches where they were born to lay their eggs.
• Crocodiles have the strongest bite of any living animal. They've barely changed in 200 million years because, well, they're already perfectly designed.

Ocean life

The oceans cover about 71% of Earth's surface, and we've only explored about 5% of them. The sea is full of creatures that seem like they belong in a science fiction movie.

• Jellyfish have been drifting through the oceans for over 500 million years, making them older than dinosaurs. Some species are bioluminescent, meaning they glow in the dark.
• Octopuses are widely considered the most intelligent invertebrates. They have three hearts, blue blood, and can change both their color and texture in milliseconds.
• Clownfish are immune to the stings of sea anemones and live among their tentacles for protection. This is one of the best-known examples of symbiosis in nature.
• The deep sea anglerfish lives in complete darkness and uses a glowing lure attached to its head to attract prey. It's one of the strangest-looking creatures on the planet.

Insects and arachnids

Insects are by far the most numerous group of animals on Earth. There are over 1 million known species, and some scientists estimate there could be 10 million or more. They might be small, but they're essential to life on our planet.

• Ants can carry objects 50 times their own body weight. If a human could do that, you'd be able to lift a car over your head.
• Monarch butterflies migrate up to 4,800 kilometers, traveling from Canada to Mexico every fall. Even more amazingly, the butterflies that return north are the great-great-grandchildren of the ones that went south.
• Dragonflies have been around for about 300 million years and are some of the most efficient hunters in the animal kingdom, catching their prey about 95% of the time.
• Spiders (which are arachnids, not insects) produce silk that is, weight for weight, stronger than steel. Some spider webs can even catch small birds.

Why animals matter

Every animal species plays a role in its ecosystem. Bees pollinate flowers that grow into the food we eat. Wolves keep deer populations in check, which helps forests grow. Earthworms break down organic matter and keep soil healthy. When one species disappears, it can have ripple effects across an entire ecosystem.

That's one of the reasons it's so important to protect wildlife and their habitats. The more kids learn about animals, the more they care about protecting them. And that gives us hope for the future.

Ready to learn more? Explore thousands of animal topics in our Animals and Nature section on Small Whale.