Unit 3 · Living Things and Where They Live

Look around your room. A cat is living. A rock is nonliving. How can you tell? Living things grow. They need water. They need air. They make new living things like themselves.

A rock does not grow. It does not eat or drink. It never has baby rocks. A toy car moves, but only when you push it. It does not need food. So it is nonliving.

A tree does not walk. But it is living. It grows taller each year. It drinks water with its roots. It makes seeds. Seeds grow into new trees.

Scientists look for clues. Does it grow? Does it need water? Does it need air? Does it make babies or seeds? If the answer is yes, it is living.

Some clues are tricky. A river moves. A fire grows bigger. But a river does not eat. A fire does not have baby fires that grow up. They are nonliving.

Mold on old bread is living. It grows. It spreads. It takes water from the bread. Even tiny things can be alive.

A plant cannot walk to a store. It makes its own food. It uses sunlight. It uses air. It uses water. Take one away, and the plant gets sick.

Roots drink water from the dirt. Leaves catch light. Leaves also take in air. That is why leaves are flat and wide. They spread out to catch the sun.

Remember Leo’s bean in the closet? It had water and air. It had no light. It turned yellow and weak. Light was the missing thing.

A plant makes its own food. An animal cannot. A rabbit must find food. It eats clover. A robin pulls up worms. A fox hunts mice.

Animals need water too. A deer drinks from a creek. Animals need air. A fish takes air from the water with its gills. A whale swims up to breathe.

Animals also need shelter. Shelter is a safe place. A bird builds a nest. A rabbit digs a hole. Shelter keeps animals warm and dry. It hides them from danger.

All animals need food. Food gives them energy to move and grow. But animals eat different things. A cow eats grass. A hawk eats mice. A raccoon eats berries and frogs.

A rabbit eats plants. A fox eats the rabbit. The fox got its energy from the rabbit. The rabbit got it from plants. The plants got it from the sun. This is a food chain.

Look at teeth for clues. Flat teeth grind plants. Sharp, pointy teeth tear meat. Your teeth have both kinds. People can eat plants and meat.

Have you seen a bumpy sidewalk? Tree roots did that. Roots grow thick and strong. They push the concrete up. Slowly, the sidewalk cracks.

A squirrel buries acorns in the fall. It forgets some of them. In spring, a tiny oak pops up. The squirrel planted a tree without knowing it.

A beaver cuts down small trees with its teeth. It builds a dam across a stream. Water backs up. A pond forms. Frogs and ducks move in. One animal changed the whole place.

People change the land a lot. We build roads. We build houses. We cut trees. We plant corn and beans in big fields. The land under Chicago was once prairie and marsh. Now it is a big city.

Changes can hurt living things. When a field becomes a parking lot, mice and birds lose their homes. Trash in a creek can hurt fish.

People can help too. We can plant trees. We can pick up trash. We can leave a corner of the yard wild for bees. In Illinois, people plant new prairies. Butterflies come back.

A kitten looks like a cat. It has fur, four legs and whiskers. But it is smaller. Its fur may be a different color. It is like its parent, but not the same.

A baby rabbit looks like its mother. A puppy looks like a dog. A baby oak tree has oak leaves. Young things grow up to look more like their parents.

Some young look very different at first. A tadpole has a tail and no legs. Then it grows legs. Its tail shrinks. It becomes a frog, like its parents.

Baby birds cannot fly. They cannot find food. They open their beaks wide and chirp. The parents fly back and forth all day. They bring worms and bugs.

A mother cat keeps her kittens warm. She licks them clean. A mother deer hides her fawn in tall grass. She comes back to feed it milk. She works to protect it.

Not all animals do this. A sea turtle lays her eggs on a beach and leaves. The babies hatch alone. They crawl to the sea by themselves.

Look at a bird’s beak. A duck’s beak is wide and flat. It scoops food from water. A hawk’s beak is sharp and hooked. It tears meat. A finch’s beak is short and thick. It cracks seeds.

Claws help too. A cat’s claws grip and climb. A squirrel’s claws hold onto bark. An eagle’s claws grab fish. A mole’s wide claws dig through dirt.

Each body part fits a job. You can guess what an animal eats by looking at its beak or claws. Scientists do this all the time.

A rose has thorns. A deer wants to eat the leaves. Ouch! The thorns poke its nose. The deer walks away. Thorns protect the plant.

A rabbit has thick fur. Fur keeps it warm in an Illinois winter. A turtle has a hard shell. It pulls its head inside. A fox cannot bite through.

A skunk has a stinky spray. A porcupine has sharp quills. A cactus has spines and a thick skin that holds water. Each part helps the living thing survive.

A habitat is the place where a living thing lives. It gives food, water, air and shelter. A pond is a habitat. A forest is a habitat.

In a pond, frogs sit on lily pads. Ducks dip for plants. Dragonflies zip over the water. Fish hide in the weeds. Cattails grow at the edge.

In a forest, tall trees make shade. Owls sleep in holes in the trunks. Deer eat leaves. Squirrels leap from branch to branch. Mushrooms grow on old logs.

Illinois is called the Prairie State. A prairie is a sea of tall grass and flowers. Few trees grow there. Grasshoppers, meadowlarks and rabbits live on the prairie.

Prairie grass has very deep roots. Some roots go down deeper than a grown-up is tall. Deep roots find water. They help the grass live through dry summers and cold winters.

A desert is dry. Little rain falls. Days are hot. A cactus stores water in its stem. A lizard hides under a rock in the heat. A kangaroo rat gets water from the seeds it eats.

Remember the bee on the purple flower? Yellow dust stuck to its legs. That dust is pollen. The bee carried it to the next flower. Now that flower can make seeds.

Bees, butterflies and hummingbirds do this. They are pollinators. The flower gives them sweet nectar. They give the flower a ride for its pollen. Both win.

Seeds travel too. A dandelion seed floats on the wind. A burr sticks to a dog’s fur. A bird eats a berry and drops the seed far away. New plants grow in new places.