Arthropod

Arthropods are a big group of animals without backbones. They are called invertebrates. These animals have a hard outer shell, called an exoskeleton, that helps protect them. This shell is made of a special material called chitin.

Arthropods have bodies made of many parts that repeat in patterns. They also have jointed parts that help them move easily. Because their hard shell cannot grow with them, arthropods go through a process called moulting. This means they shed their old shell to grow a new one.

There are many kinds of arthropods. Some live in water, while others live on land or in the air. They include insects, spiders, crabs, and many more. Arthropods have been around since the Cambrian period, which was a very long time ago.

Many arthropods are very helpful. For example, pollinators help crops grow by moving pollen from one flower to another. Arthropods also give us food. Some people eat crabs, lobsters, and even insects. The word arthropod comes from an old Greek word that means "jointed leg". A German scientist first used this word in 1843.

Even though some arthropods might seem scary, most are friendly and important parts of our world. They help keep nature balanced and provide many benefits to humans.