Insects are probably one of the most common animals in the world. Insects have six legs and a pair of feelers. Many adult insects have two pairs of wings. Some adult insects have only one pair of wings. Some do not have wings at all. The body of an insect is divided into the head, thorax and abdomen. Insects have an outer covering that is usually hard and shell-like. Most insects reproduce by laying eggs. The eggs of insects are usually very small and can be easily destroyed.
Some reptiles live on land while others live in water. Snakes, turtles, crocodiles and lizards are all reptiles. Most reptiles, except snakes, have four legs. Reptiles usually have dry and scaly skin. They breathe through their lungs. Reptiles are cold-blooded. This means that they do not have a constant body temperature like humans. Their body temperature changes with the environment that they are in. Most reptiles reproduce by laying eggs.
Some mammals live on land while others live in water. Humans, monkeys, cats and even bats have hair or fur as their outer covering. Most mammals give birth to their young alive. The females have mammary glands that can produce milk for their young. Mammals are warm-blooded, which means that they can maintain a constant body temperature. When it is hot, they can produce sweat to cool themselves down.
Jane Goodall is a scientist who studies chimpanzees and gorillas. She lived among the wild chimpanzees and gorillas in Tanzania for many years, observing how they behave. She found that chimpanzees and gorillas hug one another and make a lot of sounds — similar to how humans behave. There are so many different living things in this world. Scientists like Jane Goodall and Sir David Attenborough help us discover how different types of living things are similar to or different from us. Living things such as plants and animals can be classified based on common observable characteristics.