# Bag of Wonder: The Oak Tree > One little acorn becomes a mighty oak. Watch the seasons change and meet who lives in it! A free interactive 3D exhibit for children aged 2 to 6, from Curiosity's Child in Troy, Michigan. - Interactive exhibit: https://bagofwonder.com/look-inside/oak/ - Ages: 2 to 6. The story is pitched at the youngest; the tap cards give older children more to chew on. - Cost: free, with no sign-in, no ads and no tracking. - Works on: phones, tablets and computers, in a web browser. Sound on for the narration. ## What it is Interactive oak tree on a hill, painted in all four seasons. A time slider follows a real acorn from the moment it drops in fall, through the winter under the snow, to the root and shoot of spring, a seedling, a sapling and a mighty oak; then the oak's year: spring leaves and catkins, the green summer crown that makes the tree's food, fall color, and bare winter branches with buds. Who lives here: a squirrel's drey, a woodpecker, a resting screech owl, caterpillars, a blue jay and ladybugs in the bark. A second slider opens the acorn, and cuts into the tree to show its rings, the bark and the water pipes under it, and the roots spreading under the ground; tapping a part shows a child-friendly fact. How to play: press play to hear the story (read aloud in Kelly's voice, with the words on screen). Slide the time slider back and forth to see any part again. Slide "Pull apart" to see what is hidden inside. Tap any glowing button for a fact. ## The story 1. This is a mighty oak tree, poppets. In fall, it drops its acorns. Plop! One little acorn lands in the grass, and there it waits all winter, under the leaves and the snow. 2. In spring, the acorn splits open. A little root grows down into the soil to drink, and a shoot reaches up toward the light. 3. Year after year it grows: a seedling, then a sapling, and after many, many years, a mighty oak. This oak is older than your grandma's grandma! 4. Spring! The oak grows soft new leaves. It has flowers, too: dangly catkins full of pollen, and tiny flowers that will become acorns. 5. Summer! The oak is full of green leaves. Each leaf catches the sunlight, and with air and water, it makes food for the tree. 6. Fall! The green fades away, and the yellows and browns that were hiding underneath show through. Some leaves turn red, too. Down come the leaves and the acorns. 7. Winter. The branches are bare, and the tree rests. But look closely: tiny buds are already waiting for spring. 8. Who lives in an oak? A squirrel, with its leafy nest called a drey. A woodpecker at its hole, and an owl resting by day. Caterpillars munching leaves, and a noisy blue jay! 9. In winter, ladybugs tuck into cracks in the bark to keep cozy. Squirrels don't sleep all winter. They stay snug in their drey, and come out to find food. 10. Let's look inside! A slice of the trunk shows rings, one for every year. Under the bark, tiny pipes carry water up, and under the ground, the roots spread out as wide as the branches. 11. In fall, squirrels and blue jays bury acorns to eat later, and they forget some. In spring, those acorns grow into new little oaks. The animals plant the forest! ## The parts, and what we tell children These are the tap cards, word for word. - **Acorn**: An acorn is the oak tree's seed. Inside its shell is a baby oak, and a big store of food to help it grow. - **Acorn cap**: The little cap held the acorn onto its twig. It is covered in tiny scales, like a knitted hat. - **Shell**: A tough, shiny shell keeps the seed inside safe and dry. - **Food store**: Most of the acorn is two big, fat seed leaves full of food. The baby oak lives on this food until its own leaves grow. - **Baby oak**: Near the pointy end is a tiny baby plant, with a baby root and a baby shoot, waiting to grow. - **First root**: The root always grows first, and it grows down, to hold on tight and drink water from the soil. - **Shoot**: The shoot grows up toward the light, and its first little leaves unfold. - **Seedling**: A baby tree with just a few leaves is called a seedling. Oaks grow slowly: after its first year it may be only as tall as your hand. - **Sapling**: When a young tree is taller than you, but its trunk is still thin, it is called a sapling. - **Oak tree**: A big oak can live for hundreds of years. This one is older than your grandma's grandma! - **Catkins**: Catkins are the oak's dangly flowers. They are full of yellow dust called pollen. The wind carries the pollen to tiny flowers that will grow into acorns. - **Leaves make food**: A leaf is like a little kitchen. It uses sunlight, air and water to make sugary food for the whole tree. - **Fall colors**: Leaves are green because of a green color inside them. In fall the green fades away, and the yellows and oranges that were there all along show through. Some oak leaves make reds, too. - **Buds**: Each bud is a tiny package with next spring's leaves folded up inside, wrapped in little scales to keep them safe all winter. - **Drey**: A squirrel's nest is called a drey. It is a big ball of twigs and leaves high in the branches, soft and cozy inside. - **Gray squirrel**: Squirrels love acorns! In fall they bury lots of them to eat later. Squirrels do not sleep all winter: on cold days they stay snug in their drey, then come out to dig up their food. - **Woodpecker**: A woodpecker taps on the trunk with its strong beak, to find bugs to eat and to dig a hole for its nest. Tap, tap, tap! - **Screech owl**: This little owl rests all day in an old woodpecker hole, and wakes up at night to hunt. - **Caterpillars**: Oak trees feed hundreds of different kinds of caterpillars, more than almost any other tree. And caterpillars are food for baby birds! - **Blue jay**: Blue jays are noisy, clever birds. A jay can carry several acorns at once, and it hides them all over to eat in winter. - **Ladybugs**: In winter, ladybugs huddle together in cozy cracks in the bark, and rest until spring comes. - **Tree rings**: Every year a tree grows a new ring of wood, just under its bark. Count the rings, and you know how old the tree is! A big old oak like this might have about 200 rings. - **Bark**: Bark is the tree's skin. It is thick and rough, and it keeps the tree safe from bugs, bumps and the weather. - **Water pipes**: Under the bark are tiny pipes, too small to see. They carry water from the roots all the way up to the leaves, and sugary food from the leaves back down. - **Roots**: An oak's roots spread out under the ground as wide as its branches, and often wider. Most of them stay near the top of the soil, where the rain soaks in. - **Buried acorns**: Squirrels and blue jays bury many more acorns than they eat. The ones they forget can grow into new oak trees. - **New oaks**: Each little seedling could grow into a mighty oak, if it gets enough sunshine and rain. ## Getting the science right What we checked, and the myths we steer around: - Leaves do not "die and turn color because of the cold". In fall the tree stops making green chlorophyll and breaks down what is there; the yellow and orange pigments (carotenoids) were in the leaf all summer, hidden by the green. Reds (anthocyanins) are newly made in fall by some oaks, especially red and scarlet oaks. Shorter days and cooler nights trigger the change. - An acorn is the oak's seed inside a nut shell. Most of it is two large seed leaves (cotyledons) packed with food; the tiny embryo sits at the pointed end, and the root comes out of that tip first. - Many oaks drop acorns in fall and they sprout the next spring (red oaks need the cold winter first). White oak acorns can send a root down in fall itself; the page shows the common red-oak way: wait out the winter, sprout in spring. - The root always comes first and grows down; the shoot follows and grows up toward the light. - Oaks grow slowly and can live for hundreds of years. The page says "older than your grandma's grandma" and "about 200 rings" for its big oak: an estimate, never a specific age. - One ring is usually one year of growth (a pale spring band and a darker summer band); counting rings gives the age of that part of the trunk. Wide rings mean good growing years. - Roots: most of an oak's roots are in the top few feet of soil and spread out as far as the branches, often two or three times wider. The long deep taproot of a seedling matters less in a big old tree. The cut-away is simplified. - Under the bark, the outer wood (sapwood, xylem) carries water up from the roots; a thin layer just inside the bark (phloem) carries sugary food down. The page calls them "tiny pipes" and does not claim you can see them without a microscope. - Leaves make the tree's food from sunlight, air (carbon dioxide) and water: photosynthesis, told as "a little kitchen". - Oaks are wind-pollinated. The dangly catkins are the male flowers; the female flowers are tiny and grow into acorns. Both are on the same tree. - Squirrels do not hibernate. Gray squirrels stay in their drey on the coldest days and come out to eat food they buried. Ladybugs do overwinter in groups in bark crevices and other sheltered spots. - A drey is a squirrel's leaf nest. Eastern screech owls roost by day in tree holes, often old woodpecker holes. Hairy woodpeckers drum and dig nest holes in trunks. Oaks support more kinds of caterpillars than almost any other North American tree (hundreds of species; Doug Tallamy's figure for oaks is over 500). - Blue jays and gray squirrels cache many more acorns than they eat; forgotten ones sprout. Blue jays are thought to be major planters of oak forests (they can carry several acorns in the throat pouch and bill at once). - The animals are shown at storybook size (several times life size) so little ones can see them on the big tree; in real life a woodpecker would be a speck at that distance. - Never "secret"; nothing dangerous; nothing invites a child to climb or go inside the tree. ## How to use it with children Read "The Busy Tree" first, then watch the whole story with the sound on. At fall, pause and ask, "Where did the green go?" At "Who lives in an oak?", count the animals together and tap each one. Then pull the tree apart and count a few rings. Ask more than you tell, and let the child drive. Then step away from the screen: collect fallen leaves and acorns on a walk (look for the little caps). Make bark rubbings with crayons on paper. Plant an acorn in a pot of soil and keep it outside over winter, then watch for the root and shoot in spring. Find a tree stump and count its rings together. Acorns are not for eating, and are a choking risk for the youngest. A few minutes together is plenty. The exhibit is a doorway to the real thing, not a replacement for it. ## Credits and licenses The real scans, maps and photographs belong to their makers, under the licenses below. The words, story and code are Curiosity's Child's. - The oak on its hill in spring, summer, fall and winter, the acorn's-eye meadow and the squirrel's drey: watercolor paintings Kelly made with Grok - The acorn: real scans of a konara oak acorn and its cap by [ffish.asia / floraZia](https://sketchfab.com/ffishAsia-and-floraZia) ([CC0](https://creativecommons.org/publicdomain/zero/1.0/)) - The seedling, the sapling and the falling leaves: [PlantCatalog](https://sketchfab.com/PlantCatalog)'s "Realistic HD Northern red oak seedlings" and "Red oak leaf litter" (CC BY) - The gray squirrel: ["Eastern gray squirrel" by faerbogdan99](https://sketchfab.com/3d-models/111eaa6a9868485bb2ae71a9b409fbb8) (CC BY) - The woodpecker: ["Hairy Woodpecker" by oneillbeck](https://sketchfab.com/3d-models/c2347b204cfe45f8bc46886f006de9cd) (CC BY) - The owl: ["Eastern Screech Owl" by cmp_innovation_studio](https://sketchfab.com/3d-models/1b34de1b8208495abb37b4b629c1f8a3) (CC BY) - The blue jay: ["Blue Jay - Cyanocitta cristata" by the Moore Laboratory of Zoology](https://sketchfab.com/3d-models/bbe937f9a0ea441496159d8f7821d07f) (CC BY) - The caterpillar: [a hawk moth caterpillar scan by ffish.asia](https://sketchfab.com/3d-models/0ef9352a14f04ab08390408ee5b646a3) (CC0) - The ladybugs: ["Ladybug - insect" by Brian Trepanier](https://sketchfab.com/3d-models/ladybug-insect-42aab203e4a449e189b9b9960b3689b8) (CC BY) - Oak bark, soil and the grass clumps: [Poly Haven](https://polyhaven.com) (CC0) - The rings, the water pipes, the roots and the catkins are drawn in code - Real sounds from Freesound ([CC0](https://creativecommons.org/publicdomain/zero/1.0/), thank you!): [spring birds](https://freesound.org/s/683566/) (hargissssound), [a breeze in summer leaves](https://freesound.org/s/669113/) (kvgarlic), [October woods](https://freesound.org/s/830253/) (NickTayloe), [a winter hush](https://freesound.org/s/260634/) (lwdickens), [a woodpecker drumming](https://freesound.org/s/847353/) (kvgarlic) - Music-box waltz made for this page ## More on the Garden & Pond shelf - [The Pumpkin](https://bagofwonder.com/look-inside/pumpkin/index.md): From one little seed to a big orange pumpkin. Open it up! - [The Frog](https://bagofwonder.com/look-inside/frog/index.md): From tiny floating eggs to a wiggly tadpole to a big bullfrog. Jug-o-rum! - [The Robin](https://bagofwonder.com/look-inside/robin/index.md): Sky-blue eggs, a baby growing inside, hatching day, and first hops on the lawn. Cheep! ## About Bag of Wonder A free library of interactive 3D "look inside" science exhibits, made at Curiosity's Child, a licensed home daycare in Troy, Michigan. Secular and science-based; welcoming to all. - All exhibits and how we make them: https://bagofwonder.com/llms.txt - For grown-ups and AI assistants: https://bagofwonder.com/look-inside/about/ - To cite: "The Oak Tree", Bag of Wonder, Curiosity's Child (Troy, Michigan). https://bagofwonder.com/look-inside/oak/