Living Things, Habitats and Simple Food Chains

A mushroom is alive. So are a tree, a snail, and you. Living things share life processes. Think of these as life jobs. You may need to watch over time to spot them.

Seven life jobs

• Movement: animals walk, swim, or move body parts. Plants move slowly, too.
• Respiration: living things get energy from their food. Most use oxygen to do this.
• Sensitivity: living things sense and respond to their surroundings.
• Growth: living things grow as they develop.
• Reproduction: living things make new living things like themselves.
• Excretion: living things get rid of waste made inside their bodies.
• Nutrition: living things need food. Animals eat it; green plants make it.

Some classes remember these names with MRS GREN. Breathing and respiration have different jobs. Breathing brings air into an animal’s body. Respiration releases energy from food inside living things.

Follow a cat’s life jobs

Watch a cat walking and turning toward a sound. You can spot movement and sensing. A kitten grows into an adult cat. Cats can have kittens. The cat eats food, and respiration gives it energy. Peeing and breathing out carbon dioxide remove waste made inside its body.

You will not see all seven jobs at once. A sleeping cat is still alive. Reproduction is something living things do across their kind. A kitten does not need to have kittens to be alive.

Look slowly at a plant

A plant by a window bends toward the light over time. It senses light and moves as it grows. Roots grow down into soil. Tiny holes in leaves let gases move in and out. The plant uses sunlight to make food, then gets energy from that food. Seeds can grow into new plants.

A tree with bare branches in winter is still alive. A seed is alive and resting. With water and warmth, it can begin growing.

Movement is one clue

A car moves and uses fuel. Some cars sense nearby objects. People build cars; cars do not grow up or have young. A toy robot can move, but that alone does not make it alive.

Clouds and rivers move, too. Fire spreads and needs air, but it does not do the life jobs as a living thing does. To decide whether something is alive, look beyond movement.

A feather and a glass marble are both still. Yet they belong in different groups. To sort them, think about where each one came from.

Ask two questions

1. Is it alive now? If yes, choose living.
2. If no, was it alive, or part of something alive? If yes, choose dead. If no, choose never alive.

Use the questions in this order. A seed may look still, but it is alive. It belongs in Living before you need the second question.

An empty snail shell belongs in Dead because it came from a snail. The living snail inside a shell belongs in Living. Look carefully at what you are sorting.

Sort a walk’s finds

Imagine you find a snail, an oak tree, and a fresh acorn. All three are living. The acorn is a seed that can grow into an oak.

Next you find a dry leaf and a feather. Neither is alive now. Both came from living things, so place them in Dead.

You also find a metal bottle cap and rainwater. Neither came from a living thing. Place both in Never alive.

Find out what it is made from

People make wooden chairs and paper bags from trees. Cotton shirts come from cotton plants. Wool sweaters come from sheep’s wool. These things belong in Dead when you use these three sorting groups. A factory can turn once-living material into something new.

Compare a wooden spoon with a metal spoon. Both were made by people. The wood came from a tree, so the wooden spoon goes in Dead. The metal spoon goes in Never alive. Glass marbles and bricks also go in Never alive.

Give your reason

Draw three columns headed Living, Dead, and Never alive. Add a drawing or name for each thing. Say, “The feather goes in Dead because it came from a bird.” Your reason helps someone else follow your choice.

A dead thing can be a home for living things. A rotting log may hold worms and beetles. Sort the log and the animals separately: the log is dead, and the animals are living.

Where would you look for a water lily? A pond gives it a home that a dry desert cannot. A habitat is a plant’s or animal’s natural home. It is where the living thing finds what it needs.

Look beyond a bed

A nest is a bird’s shelter. Its habitat also has places to find food and water. A rabbit’s burrow is a shelter inside the field where it lives. A pet tank and a zoo enclosure are homes made for animals by people, not their natural habitats.

Habitats have living and non-living parts. Frogs, fish, ducks, and water plants are living parts of a pond. Water, stones, air, and sunlight are non-living parts. Both kinds matter to the living things there.

Compare places around the world

Polar bears live in the far north, in the Arctic. Antarctic penguins live in the far south. They do not share an icy home with polar bears.

Match a body to its home

A fish’s gills take oxygen from the water. A duck’s webbed feet help it paddle. Thick fur and a layer of fat keep a polar bear warm. A cactus stores water in its thick stem.

A camel’s hump stores fat, not water. The fat is a food-energy store. A camel can go a long time without drinking.

These features help living things in their own habitats. A goldfish cannot live on a dry path. A polar bear would get far too hot in a desert.

Compare a woodland and a desert

Picture a rainy woodland with shade and fallen leaves. Now picture a hot desert with very little rain. The woodland can support many trees and mushrooms. Desert plants and animals must cope with little water.

You can find habitats nearby, too. A park, hedge, stream, backyard, or school field may be a natural home for many living things.

A whole woodland can be a habitat. Under one fallen log, you can find a much smaller home. A microhabitat is a tiny habitat inside a bigger one. “Micro” means very small.

Notice the tiny places

Look under a stone or log, among dead leaves, or in tree bark. A wall crack and a patch of long grass can be microhabitats. You can find them in a schoolyard as well as a forest.

Two places side by side can feel very different. Under a log, the ground is often dark, damp, and cool. An open path beside it can be bright and dry. Those differences help explain which creatures you find.

Match small creatures to their needs

Pill bugs and earthworms lose water easily. Damp places help keep them from drying out. Rotting wood and dead leaves give pill bugs and millipedes food. A log can also hide small creatures from hungry birds.

You might find slugs, snails, beetles, ants, spiders, or centipedes nearby. They are not all insects. An insect has six legs. A spider has eight. An adult pill bug has fourteen. Pill bugs are a kind of woodlouse, often called roly-polies.

Compare a log and a path

A class finds 6 pill bugs, 3 earthworms, 2 slugs, and 1 centipede under a log. Add the animals: 6 plus 3 plus 2 plus 1 makes 12 animals. There are 4 kinds.

On the open path, the class finds 2 ants of one kind. The log has more animals and more kinds in this search. Its damp ground, food, and shelter help explain the difference.

Watch a simple tray test

An adult sets up a tray for 10 pill bugs. One half is damp and dark. The other half is dry and bright. After 10 minutes, 8 are on the damp, dark side. Two are on the dry, bright side.

Most chose the damp, dark side in this test. The class repeats the test to check the result, then returns the animals to their home.

A good home has more than somewhere to sleep. A habitat must meet the needs of the living things there. Plants and animals also help meet each other’s needs.

What do living things need?

Animals need food, water, air, shelter, space, and the right warmth. Shelter gives them somewhere to rest, hide, and raise young.

Plants need light, water, air, warmth, space, and nutrients. Nutrients are useful substances plants take in, usually from soil. Plants make their food using light; nutrients are not their food.

Follow a squirrel through a woodland

A squirrel eats acorns, nuts, and seeds from trees. It drinks from puddles or streams. A hole in a trunk or a nest gives shelter. The trees and ground give it space to climb and run.

Now look at a frog beside a pond. The water keeps its skin moist and gives it somewhere to lay eggs. Nearby insects give it food. Water plants and mud give hiding places.

How plants help animals

Leaves, nuts, seeds, fruits, and nectar can feed animals. Birds nest in trees, and insects hide in grass. Green plants also give off oxygen, a gas animals need to breathe.

How animals help plants

A bee visits a flower for nectar. Pollen sticks to its body. When the bee visits another flower, it carries pollen there. This pollination helps flowering plants make seeds. Butterflies can carry pollen, too.

Animals also spread seeds. A bird eats berries and later drops seeds in a new place. A squirrel buries acorns and leaves some behind. Burrs catch on fur, travel with an animal, and fall off elsewhere. Seeds can then grow away from the parent plant.

Animals can help other animals, too. An owl may use a tree hole made earlier by a woodpecker. Many animals also depend on others for food.

What happens when a home changes?

If a pond dries up, fish lose the water they need. Frogs may need to move. If woodland trees are cut down, squirrels lose both food and shelter.

People can help by growing flowers for bees or leaving a log pile for tiny creatures. Litter can trap animals or make them sick if eaten. Put litter in a trash can so it stays out of their homes.

You can find out what lives nearby by looking carefully. A habitat hunt, or survey, records living things in one place. Start with a question, such as “What lives under our school’s logs?”

Get ready

Choose a place with an adult. Take a pencil, clipboard, and picture chart. A magnifying glass helps you see tiny details. A camera can record a find without moving it. A clear bug viewer and soft paintbrush can help with a brief, gentle look.

Stay with an adult, especially near water. Do not touch or eat wild mushrooms or berries. Wash your hands after handling soil, plants, or animals.

Search without spoiling the home

1. Look high in trees, in bushes, and low on the ground.
2. Lift a small log or stone gently with your adult.
3. Look, count, and record what is there.
4. Return creatures to the same place after a short look.
5. Put the log or stone back as you found it.

Leave flowers growing. Handle small creatures gently or watch without touching. Their habitat should still meet their needs after you leave.

Make a useful record

Write a name, draw a picture, or take a photo. Use your picture chart to help name a find. If you do not know its name, record what you see. “Six legs and a shiny black body” is more useful than guessing.

Plants belong in your record, too. Look for grass, clover, dandelions, trees, and moss. A hunt that lists only animals misses part of the life there.

Record animal signs in a separate part of your page. Footprints, chewed leaves, birdsong, webs, and shiny snail trails show that animals have been there. A web is a sign of a spider, even if the spider is hidden.

Keep count with tally marks

Make one mark for each animal you count. Draw four upright lines. Draw the fifth line across them to make a bundle of five. For 7 ants, draw one bundle and two more lines. Five and two make seven.

Try another time

Rain can bring earthworms, slugs, and snails out. Some animals hide by day and come out at night. Note when you looked and what the weather was like. Another visit may reveal living things you missed the first time.

Finding lots of animals and finding lots of kinds are different things. Biodiversity means the variety of living things in a place. To compare variety, count different kinds, including plants.

Count each kind once

Look at this list: ant, ant, ant, snail, ant, earthworm, snail. There are 7 animals. If the ants are all the same kind, there are 3 kinds: ant, snail, and earthworm.

Point to each new kind as you count. More ants make the animal total bigger. They do not add another kind when they are the same kind of ant.

Compare two class records

A class spends 10 minutes at each of two places. Here is what it finds.

The pond record has 5 more kinds. Count the plants as well as the animals. Grass appears in both records. Frogs appear only in the pond record; the pigeon appears only in the playground record.

These records tell you what the class found on its visits. Hidden animals may be missed. Seeing no animals does not mean the place has no life. Plants may be there, and animal signs can show visitors.

Show and explain the difference

Make a table, or draw one bar for each place. Let each step up the bar stand for one kind. The pond bar reaches 9; the playground bar reaches 4.

Next, look at the homes. Water, mud, shade, and many plants can meet different needs. A place with many kinds of plants can offer different foods and hiding places. That helps explain why it supports many kinds of animals.

Watch out for a large total

A lawn with 50 ants of one kind has many animals. A log pile with 12 animals of 5 kinds has more animal variety. The smaller total can have more kinds.

Living things depend on each other. If one kind disappears, animals that ate it may lose food. Animals using it for shelter may lose their hiding place. Your records help you notice what a habitat offers.

A leaf and a rabbit get food in different ways. A green plant makes food. An animal gets food by eating plants, animals, or both.

How a plant gets food

Green plants use sunlight, water, and a gas called carbon dioxide from the air. They make food in their leaves. Roots take up water and small amounts of minerals from the soil. Soil itself is not the plant’s food.

Sunlight helps a plant make food. The plant does not eat the Sun. It uses the light reaching its leaves.

Find an animal’s food sources

A food source is something a living thing gets food from. Rabbits eat grass and leaves. Caterpillars eat leaves. Squirrels eat nuts and seeds. Owls eat mice. Robins eat earthworms, insects, and berries. Foxes eat rabbits, mice, and berries.

These words describe what animals eat. An omnivore gets food from both plant and animal sources.

Trace a meal back

Start with an owl eating a mouse. What did the mouse eat? Seeds. Where did the seeds come from? A plant. The owl depends on plants through the food its prey eats.

If the plants providing its prey’s food disappear, the meat-eater’s food can become scarce, too.

Follow your breakfast

People are animals, and our food comes from living things. Think about cereal, milk, and an egg.

• Cereal comes from grains such as wheat or corn. These are plants.
• Milk comes from a cow. The cow ate plants such as grass.
• An egg comes from a hen. The hen ate food such as grain.

A store sells the breakfast, but it is not where the food first began. You can trace each part back to a plant, sometimes through an animal.

You can show who eats whom with a food chain. Each link is food for the next living thing. Read an arrow as “is eaten by.”

Follow the arrow

Grass → rabbit → fox

Read the first arrow: “Grass is eaten by the rabbit.” Read the next: “The rabbit is eaten by the fox.” The arrow points from the food toward the eater. It follows where the food goes.

Build a chain one link at a time

You have three cards: owl, seeds, and mouse.

1. Find the plant or plant part. Put seeds first.
2. Find the animal that eats seeds. Put mouse next.
3. Find the animal that eats the mouse. Put owl last.
4. Draw arrows pointing to each eater: seeds → mouse → owl.
5. Read both arrows aloud to check each link.

“Seeds are eaten by the mouse” makes sense. “The mouse is eaten by the owl” makes sense, too.

Check the direction

Suppose someone draws fox → rabbit. Reading it gives “The fox is eaten by the rabbit.” That reverses who eats whom. Turn the arrow around: rabbit → fox.

A simple food chain starts with a green plant or a plant part. Leaves, seeds, fruit, or nectar can begin the chain. A picture may show the Sun beside a plant to show its light source. The Sun is not food, so do not give it a food-chain link.

Count the links

Grass → cow has two living things and one arrow.

Leaves → caterpillar → robin → hawk has four links and three arrows. Each arrow joins two neighbors, so there is one fewer arrow than links. When leaves stand for the plant, they count as its link.

Follow food, not size

The biggest animal does not have to be last. A weasel can hunt and eat a rabbit larger than itself. So grass → rabbit → weasel follows the food even though the last animal is smaller.

Each living thing has a job in a food chain. Some words name how it gets food. Others tell you about hunting.

Who makes food? Who eats it?

A producer makes its own food. The green plant at the start of a chain is a producer. A consumer gets food by eating other living things. All the animals in the chain are consumers.

In grass → rabbit → fox, grass is the producer. The rabbit and fox are consumers. Making eggs or having young does not make an animal a producer. “Producer” names food-making, not having babies.

A predator hunts and eats another animal. Prey is the animal hunted and eaten. The fox is a predator; the rabbit is its prey. A rabbit eating grass is a consumer, but eating a plant does not make it a predator.

Can one animal do both?

Look at grass → grasshopper → frog → snake. The frog hunts grasshoppers, so it is a predator. The snake eats the frog, so the frog is prey, too. Look at both sides of the animal’s place in the chain.

Find chains in different habitats

Food chains show feeding in a particular place.

• Garden: lettuce → slug → toad.
• Woodland: acorns → squirrel → hawk.
• Seashore: seaweed → sea snail → crab.
• Pond: algae → tadpole → fish → heron.
• Ocean near Antarctica: algae → krill → penguin → leopard seal.

Algae are simple living things that make food using light. Some are tiny and float in water. Seaweed is a large kind of algae. They play the food-making role in these water chains.

One animal can appear in different chains. A fox eats rabbits and mice. Grass → rabbit → fox and seeds → mouse → fox can both show its food.

People are consumers, too. Wheat can become bread that a person eats. Grass can feed a cow that gives people milk or meat.

Follow a change through the chain

Use grass → rabbit → fox. A very dry summer kills much of the grass. First, rabbits have less food. There may then be fewer rabbits. Foxes have less food because they eat rabbits.

Now imagine the foxes disappear. More rabbits may survive. More rabbits can eat more grass. A change at one link can reach other living things through their feeding needs.