Category Plants & Animals

Arthropod of the Sea

Many kinds of arthropods live in the sea. Lobsters, shrimps, crabs, and barnacles are all arthropods that live in the sea. They are called crustaceans. That means animals with crusts. Every part of a lobster’s body is covered with a crust of hard skin, like armour. Crustaceans have hard shells, 10 leg and 4 feelers, or antennae. Because they live mostly in the water, crustaceans breathe with gills, like fish.

Lobsters use eight of their ten legs for walking along ocean floor. The other two legs are used like arms. Each arm ends in a fierce-looking pincer, or claw. Shrimps look like tiny lobsters. Some kinds of shrimps are so small they can be seen only with a microscope.

Crabs have flat bodies. The tail is tucked forwards under the rest of the body. Instead of walking forwards, crabs scuttle sideways along the seashore or in shallow rock pools. Barnacles are crustaceans that fasten themselves to rocks or the bottoms of ships. They are closed up inside their shells, and only their legs stick out. They wiggle their legs to pull in food that floats past in the water.

The Web Weavers

Many kinds of spiders spin webs to catch flying insects. Each kind of spider makes its own special kind of web, from small, sticky traps to large, tightly woven nets. Orb spiders make webs with threads that stretch from the centre like the spokes of a bicycle wheel. Black widow spiders make tangled webs. Grass spiders make webs like little sheets.

Spider webs are made of silk that comes out of the spider’s body. The silk is a liquid that forms a thin, strong thread when air touches it. After a spider spins its web, it hangs underneath it or hides nearby. An insect caught in the web shakes the web as it struggles, telling the spider that dinner is ready!

Some spiders have other ways to catch their food. Wolf spiders and lynx spiders chase insects. Jumping spiders catch insects by jumping on them. Some spiders even like to fish! They wait beside a stream or pond and catch water insects that swim past.

Crawling on Eight Legs

Many people shudder when they see a spider. But most spiders are harmless, and some are even helpful. How do spiders help people? They eat many harmful insects. They munch grasshoppers and locusts, which destroy crops. They also snap up flies and mosquitoes, which carry disease.

Many people think spiders are insects. But they are not. Insects have wings, feelers, and six legs. Spiders have neither wings nor feelers, and they have eight legs. Eight-legged animals are called arachnids.

Scorpions are close relatives of spiders. Scorpions live in warm, dry places such as deserts. Scorpions have eight legs, like spiders. But mother scorpions don’t lay eggs, as many spiders do. Baby scorpions come out of the mother’s body. They climb up onto her back and hang on as she carries them around.

A scorpion uses its claws to grab its prey. Then it pulls the victim into its mouth and chews it up. Sometimes the scorpion kills its prey with a poisonous sting. The stinger is a sharp, curved spike at the end of the scorpion’s tail. The stings of some scorpions are dangerous to people.

Wood-Ant City

An ant nest is like a little city where hundreds or even thousands of ants live together. Ants make their nests by digging tunnels and storerooms in the ground. Some also build mounds aboveground and cover them with twigs and pine needles.

The picture shows on wood-ant nest. If you look at it carefully, you can see that a lot is going on. Above the nest, a group of workers hunts for food. The ant with wings is a male. Male ants don’t do any work.

Inside the nest, in the top tunnel, two workers are bringing in part of a leaf. They will use it to repair the nest. Other workers are getting ready to carry cocoons to another room. Inside each cocoon is a baby ant. When the young ants grow up, they will break out of the cocoons.

In the lower tunnel is the queen ant. She is much bigger than the workers. She spends her whole life laying eggs. Ants work as if they were quite clever, but an ant does things because its body gets signals, such as smells. Different smells make ants do different things.

The Buzz on Bees

A honey bee lands on a flower. It stretches out its tube-like tongue and sucks up the sweet nectar. As the beep pushes into the flower, a yellow powder called pollen falls onto the bee’s hairy body. The pollen then rubs off on every flower the bee visits after that. A flower needs pollen from another flower of the same kind to make seeds.

Honey bees also take some pollen for themselves. They mix it with a tiny bit of nectar and carry it on their back legs. When the bee is fully loaded with nectar and pollen, it flies back to the hive. There worker bees take the nectar and pollen. In a few days the nectar will thicken to honey.

Inside the hive there are thousands of tiny rooms, or cells. The cells are storerooms. Some are filled with honey or pollen, food for the bees. Others contain eggs or bee larvae. Others hold baby bees in silky cocoons. These young bees are changing into adults.

Tiny, but Deadly

When you think about dangerous animals, do you think of fierce sharks and hungry lions? You should also think about another dangerous animal—the common housefly. Why? Because flies carry germs, and some germs cause disease!

Flies taste things with their feet. As they walk over all kinds of rotting foods and plants, they collect germs on their feet. Then they land on fresh food, leaving germs everywhere.

Flies also spread germs when they eat. A fly can eat only liquids. It pumps a special juice from its stomach that turns food into liquid. The fly might suck up food that has germs in it. This means some of the germs get into the fly’s stomach. If the fly pumps some stomach juice onto the sugar on your table, the germs get into the sugar. And if you eat the sugar, the germs get into you!

The mosquito can also be a dangerous enemy. Female mosquitoes drink people’s blood! They break the skin and suck the blood with their female mosquito long mouthparts, leaving an itchy bite. Sometimes, when mosquitoes drink blood, they inject tiny germs into the bloodstream. The germs mosquitoes carry can cause serious diseases.