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LET'S EXPLORE The animal kingdom

Let's explore the animal kingdom

A tardigradeA tardigradeAnimals are living things that can move about and must eat food to survive. This food may be plants, other animals, or both. Some animals are bigger than houses, while others are tinier than a dot on your screen. Animals are divided into two groups: vertebrates (animals with backbones) and invertebrates (animals without backbones). Vertebrates include fish, amphibians, reptiles, birds and mammals. Insects, spiders, worms and molluscs are all invertebrates.

A humpback whale breachingA humpback whale breaching

Invertebrates living above and below groundInvertebrates living above and below ground


Invertebrate animals do not have a backbone. By far the biggest group of invertebrates are the arthropod group (the name means “joined legs”). It includes insects, arachnids (spiders and scorpions) and crustaceans (crabs and shrimps). Other invertebrates are: worms, millipedes, centipedes, sponges, molluscs (snails, slugs, bivalves, octopuses and squid), echinoderms (starfish and sea urchins) and cnidarians (jellyfish and sea anemones).


Around two million species (kinds) of animal are known to us. Scientists say there may as many as 30 million species yet to be discovered.

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