A growing caterpillar正在長大的毛毛蟲
Read the label under it. How many times has it shed its skin so far?
看看牠下面的標籤。到現在牠蛻了幾次皮？
Living Things · Unit 3 · Lesson 11 · 生命與生態 單元三 第十一課
How Does a Caterpillar Become a Butterfly?毛毛蟲怎麼變成蝴蝶？
A caterpillar and a butterfly do not look like relatives, and yet they are the same animal at two different ages. In a 3D model, follow one insect from an egg on a leaf to a caterpillar that outgrows its skin again and again, and then into a chrysalis. Look inside the chrysalis while the body is taken apart and built again. Watch the new butterfly open its wings. Last, find out which insects go through this great change and which do not.
毛毛蟲和蝴蝶看起來一點也不像親戚，但牠們其實是同一隻動物，只是年紀不同。在 3D 模型裡，跟著一隻昆蟲，從葉子上的卵，到一次又一次把皮撐破的毛毛蟲，再到蛹。看看蛹的裡面：身體被拆開，再重新蓋起來。看剛出來的蝴蝶把翅膀撐開。最後查一查，哪些昆蟲會經歷這樣的大改造，哪些不會。
Big idea · 一句話看懂
A butterfly lives its life in four stages: egg, caterpillar, chrysalis, and adult. The caterpillar has one job, which is to eat and grow. The adult has a different job, which is to fly, find a mate, and lay eggs. Between them comes the chrysalis. Inside it, most of the caterpillar's body is broken down, and the adult's body grows from small groups of cells that the caterpillar carried all along. Both bodies are built from the same set of instructions.
蝴蝶的一生分成四個階段：卵、毛毛蟲、蛹、成蟲。毛毛蟲只有一個工作：吃，然後長大。成蟲的工作不一樣：飛行、找伴侶、產卵。夾在中間的是蛹。在蛹裡面，毛毛蟲大部分的身體被分解掉，而成蟲的身體，是從毛毛蟲一直帶在身上的幾小團細胞長出來的。兩種身體，用的是同一份說明書。
3D Model · 3D 模型
One Animal, Four Stages 同一隻動物，四個階段
Drag to turn the model, and scroll or pinch to zoom. Press Pause, and move the Time slider slowly from one end to the other. Watch the caterpillar. It does not grow smoothly. It grows in jumps. When you reach the chrysalis, switch on See inside the chrysalis and keep moving the slider. What disappears, and what appears?
拖曳可以旋轉模型，滾輪或雙指可以縮放。按「暫停」，把「時間」滑桿從一頭慢慢拉到另一頭。注意毛毛蟲：牠不是平順地長大，而是一跳一跳地長。到了蛹的階段，打開「看蛹裡面」，繼續拉動滑桿。什麼東西不見了？什麼東西出現了？
Drag to turn · 拖曳旋轉 Scroll or pinch to zoom · 滾輪／雙指縮放
This 3D model needs WebGL, which this browser does not support. The reading and the cards below still explain everything.
這個瀏覽器不支援 WebGL，無法顯示 3D 模型；下方的課文與卡片一樣能看懂。
- Cream: the egg
米白色：卵 - Green and yellow: the caterpillar
綠色和黃色：毛毛蟲 - Green case: the chrysalis
綠色的殼：蛹 - Orange: the adult's wings
橘色：成蟲的翅膀
A teaching model. The time slider is not in days. The egg, the caterpillar, and the chrysalis each last from days to weeks, and it differs from one kind of butterfly to another. The five growth steps follow the monarch butterfly. The view inside the chrysalis is a simple picture of a very complicated change. The insect is drawn as a general butterfly and is not any one species.
這是教學用的模型。時間滑桿的單位不是天；卵、毛毛蟲和蛹各自持續幾天到幾個星期，每一種蝴蝶都不一樣。五個成長的階段（五齡）是以帝王斑蝶為例。蛹裡面的畫面，只是把一個非常複雜的變化畫成簡單的樣子。這隻昆蟲畫的是一般的蝴蝶，不是哪一個特定的種類。
Model drawn by My Culture Connect as a teaching diagram. The ideas follow the sources listed at the bottom of this page. · 模型由人師教育協會自繪示意；原理依本頁最下方列出的出處。
Reading · 英文閱讀
11
Unit 11: How Does a Caterpillar Become a Butterfly?
If you had never been told, would you guess that a caterpillar and a butterfly are the same animal? One crawls and chews leaves. The other flies and sips from flowers. They have different mouths, different legs, and different eyes. And yet every butterfly was once a caterpillar.
要是從來沒有人告訴你，你猜得到毛毛蟲和蝴蝶是同一種動物嗎？一個用爬的、啃葉子；另一個用飛的、吸花蜜。牠們的嘴不一樣、腳不一樣、眼睛也不一樣。可是每一隻蝴蝶，都曾經是一隻毛毛蟲。
The story starts with an egg. A female butterfly lays it on a plant that her young can eat. Out of the egg comes a tiny caterpillar, and it starts eating at once.
故事從一顆卵開始。雌蝶把卵產在孩子可以吃的植物上。從卵裡出來一隻很小的毛毛蟲，一出來就開始吃。
A caterpillar's whole life is eating and growing. Its skin does not grow with it, so from time to time the old skin splits and the caterpillar crawls out in a new, larger one. A monarch caterpillar does this in five steps.
毛毛蟲的一生就是吃和長大。牠的皮不會跟著長，所以每隔一陣子，舊皮就裂開，毛毛蟲穿著一層比較大的新皮爬出來。帝王斑蝶的毛毛蟲分五個階段這樣長大。
When it is fully grown, the caterpillar stops eating and sheds its skin one last time. What appears is a chrysalis, a hard case that hangs still. Inside, most of the caterpillar's body is broken down. The adult's body is built from small groups of cells that the caterpillar has carried since it hatched. These cells become the wings, the legs, and the eyes of the butterfly.
長到最大以後，毛毛蟲不再吃東西，最後一次蛻皮。這次出現的是蛹——一個掛著不動的硬殼。在裡面，毛毛蟲大部分的身體被分解掉；成蟲的身體，是用毛毛蟲從孵化起就帶在身上的幾小團細胞蓋起來的。這些細胞變成蝴蝶的翅膀、腳和眼睛。
At last the case splits, and the butterfly climbs out. Its wings are soft and folded. It hangs and waits while they open and dry, and then it flies away.
最後殼裂開，蝴蝶爬出來。牠的翅膀又軟又皺。牠掛著等翅膀撐開、變乾，然後才飛走。
Why go to so much trouble? One reason is that the young and the adults do not get in each other's way. The caterpillar eats leaves, and the butterfly drinks nectar, so they are not competing for food. Each body is built for one job.
為什麼要這麼大費周章？原因之一是：小的和大的不會互相妨礙。毛毛蟲吃葉子，蝴蝶喝花蜜，所以牠們不必搶食物。每一種身體，都只為了一種工作而打造。
Read aloud · 課文朗讀
Questions · 閱讀理解
What are the four stages in the life of a butterfly?
Egg, caterpillar, chrysalis, and adult.
Why does a caterpillar shed its skin?
Its skin does not grow with it, so it has to change to a larger one.
What is one advantage of having two very different bodies?
The young and the adults eat different food, so they do not compete with each other.
Words & Phrases · 生字及片語
caterpillar(n.)毛毛蟲The caterpillar ate the whole leaf.毛毛蟲把整片葉子吃光了。butterfly(n.)蝴蝶A butterfly landed on my hand.一隻蝴蝶停在我的手上。egg(n.)卵；蛋She lays each egg on a leaf.牠把每一顆卵產在葉子上。stage(n.)階段Its life has four stages.牠的一生有四個階段。shed(v.)蛻（皮）；脫落The caterpillar sheds its skin as it grows.毛毛蟲長大的時候會蛻皮。skin(n.)皮膚；皮Its old skin is too tight.牠的舊皮太緊了。adult(n.)成蟲；成年的動物The adult has wings.成蟲有翅膀。insect(n.)昆蟲A butterfly is an insect.蝴蝶是一種昆蟲。
Quick Check · 小測驗
1. What comes between the caterpillar and the adult butterfly?
2. What is a caterpillar's main job?
3. Why does a caterpillar shed its skin?
4. What happens inside the chrysalis?
5. Why can a new butterfly not fly at once?
Four Stages, or Three? · 四個階段，還是三個？
Not every insect has a chrysalis 不是每一種昆蟲都有蛹
Some insects change completely, as butterflies do. Others hatch looking like small adults without wings, and simply grow. Choose an insect and see which kind it is.
有些昆蟲像蝴蝶一樣徹底改頭換面；有些一孵出來就像沒有翅膀的小號成蟲，只是慢慢長大。選一種昆蟲，看牠是哪一類。
Choose an insect · 選一種昆蟲
Scientists call the first kind complete metamorphosis and the second kind partial, or incomplete, metamorphosis.科學家把第一類叫做「完全變態」，第二類叫做「不完全變態」。
Stages in its life · 一生有幾個階段
Try It in the Model · 在模型裡試試
Four moments to look at 四個值得看的時刻
The caterpillar grows but never changes shape. The chrysalis changes shape but does not grow. The butterfly does neither. Each stage does one thing.
毛毛蟲會長大，但形狀不變；蛹會改變形狀，但不長大；蝴蝶兩樣都不做。每個階段只做一件事。
Inside the chrysalis蛹的裡面
The green shape is shrinking, and the orange shapes are growing. What are they?
綠色的那一團在縮小，橘色的東西在長大。它們是什麼？
Just out剛出來
The butterfly is out, but look at its wings. Move the slider a little further.
蝴蝶出來了，可是看看牠的翅膀。把滑桿再往前拉一點。
Ready to fly可以飛了
Compare this body with the caterpillar's. What does each one have that the other lacks?
把這個身體和毛毛蟲的比一比。各自有什麼是對方沒有的？
Go Further · 延伸閱讀
The instructions, and the flowers 說明書，還有花
Living Things · Lesson 3 · 生命與生態 第三課What Is DNA?DNA 是什麼？One set of instructions builds both the caterpillar and the butterfly.同一份說明書，蓋出了毛毛蟲，也蓋出了蝴蝶。Go to the lesson · 前往這一課 →Living Things · Lesson 6 · 生命與生態 第六課Why Do Flowers Bloom?花為什麼要開？See what the adult butterfly does for the flowers it visits.看看成蟲去拜訪花朵的時候，替花做了什麼。Go to the lesson · 前往這一課 →
Change by the Numbers · 變態的數字
Six numbers about growing up as an insect 六個和昆蟲長大有關的數字
How many stages, how many skins, and how many butterflies in one valley.
幾個階段、幾層皮，還有一座山谷裡有多少隻蝴蝶。
4stages · 個階段
Egg, larva, pupa, and adult. Butterflies, beetles, flies, and bees all grow up this way.卵、幼蟲、蛹、成蟲。蝴蝶、甲蟲、蒼蠅和蜜蜂都是這樣長大的。
3stages · 個階段
Egg, nymph, and adult. Grasshoppers, dragonflies, and cicadas skip the pupa.卵、若蟲、成蟲。蝗蟲、蜻蜓和蟬沒有蛹的階段。
5growth steps · 齡
A monarch caterpillar grows in five steps, shedding its skin at the end of each.帝王斑蝶的毛毛蟲分五個階段長大，每個階段結束時蛻一次皮。
2weeks · 個星期
A monarch comes out of its chrysalis after about this long.帝王斑蝶大約過這麼久，就從蛹裡出來。
14 cmlong · 長
The largest caterpillars reach this length. The smallest are about 1 millimeter.最大的毛毛蟲可以長到這麼長；最小的大約只有 1 毫米。
30+valleys · 處山谷
Taiwan has more than this many valleys where milkweed butterflies gather to spend the winter.台灣有超過這麼多處山谷，是斑蝶聚在一起過冬的地方。
Butterfly Stories · 蝴蝶的故事
A painter who watched, a memory that survives, a worm that spins, and a purple valley 一位仔細觀察的畫家、留下來的記憶、會吐絲的蟲，還有一座紫色的山谷
What people have learned by keeping caterpillars and waiting.
人們養著毛毛蟲、耐心等待之後學到的事。
1647–1717
The painter who watched仔細觀察的畫家
In the 1600s, many people in Europe believed that insects simply appeared by themselves, without parents. Maria Sibylla Merian, a German artist, did not take anyone's word for it. She kept caterpillars, fed them, and painted every stage as it changed into the next. Her careful pictures helped to show that insects have a life cycle, and that each butterfly comes from an egg laid by another butterfly.
十七世紀的歐洲，很多人相信昆蟲是自己冒出來的，沒有爸媽。德國畫家梅里安不肯人云亦云。她自己養毛毛蟲、餵牠們，把每一個階段怎麼變成下一個階段都畫下來。她仔細的畫作，幫助人們明白昆蟲有自己的生命週期：每一隻蝴蝶，都來自另一隻蝴蝶產下的卵。
2008
Does a moth remember being a caterpillar?蛾記得自己當過毛毛蟲嗎？
If the body is taken apart inside the pupa, is everything lost? In 2008, scientists reported an experiment with a moth called the tobacco hornworm. They trained the caterpillars to behave in a certain way. After the change, the adult moths still behaved that way. So something is carried through, and the pupa is not a completely fresh start.
身體在蛹裡被拆開，是不是什麼都沒留下？2008 年，科學家發表了一項用菸草天蛾做的實驗：他們訓練毛毛蟲學會一種行為，結果變成成蟲以後，這些蛾仍然保有這種行為。所以有些東西被帶過去了——蛹並不是徹底的從頭來過。
Silk · 絲
A case made of thread用線做的殼
A butterfly's chrysalis is bare. Many moths add something more. A silkworm, which is the caterpillar of a moth, eats mulberry leaves and sheds its skin four times. Then it spins a cocoon of silk around itself and becomes a pupa inside. People learned long ago to unwind that thread and weave it into cloth.
蝴蝶的蛹是光溜溜的；很多蛾則多加了一層。蠶是一種蛾的幼蟲，牠吃桑葉、蛻四次皮，然後吐絲把自己包成一個繭，在裡面變成蛹。人類很早以前就學會把這條絲線抽出來，織成布。
Taiwan · 台灣
The purple butterfly valleys紫蝶幽谷
The purple crow butterflies of Taiwan do something unusual. Before winter, great numbers of adults fly south and gather in sheltered valleys, where they wait out the cold together. In spring they fly north again, along a route that passes over Bagua Mountain in Changhua. The Maolin National Scenic Area explains that a purple butterfly valley is not one place but a way of living. Taiwan has more than thirty such valleys, and Maolin in Kaohsiung has at least ten.
台灣的紫斑蝶有不尋常的做法：冬天來臨之前，大批成蟲往南飛，聚在背風的山谷裡，一起度過寒冷的日子；春天再往北飛回去，北返的路線會經過彰化的八卦山。茂林國家風景區管理處說明：「紫蝶幽谷」不是一個地名，而是一種生態現象；台灣有超過三十處這樣的山谷，高雄的茂林就有至少十處。
Myth vs. Fact · 常見迷思
Four things people get wrong 四個常見的誤會
✗ Myth · 迷思A caterpillar and a butterfly are two different animals.毛毛蟲和蝴蝶是兩種不同的動物。
✓ Fact · 事實They are one animal at two stages of its life.牠們是同一隻動物的兩個生命階段。
✗ Myth · 迷思The caterpillar rests inside the chrysalis and grows wings.毛毛蟲在蛹裡休息，然後長出翅膀。
✓ Fact · 事實Most of its body is broken down, and a new body is built.牠大部分的身體被分解掉，再蓋出一個新的身體。
✗ Myth · 迷思A small butterfly will grow into a big one.小蝴蝶會長成大蝴蝶。
✓ Fact · 事實Adult butterflies do not grow. All the growing is done by the caterpillar.蝴蝶成蟲不會再長大；所有的成長都是毛毛蟲完成的。
✗ Myth · 迷思All insects have a caterpillar stage and a pupa.所有的昆蟲都有毛毛蟲和蛹的階段。
✓ Fact · 事實Grasshoppers, dragonflies, and cicadas have no pupa. Their young are called nymphs.蝗蟲、蜻蜓和蟬沒有蛹；牠們的幼體叫做若蟲。
Remember It · 記憶口訣
The change in a sentence 一句話記住變態
Four stages四個階段
Egg, caterpillar, chrysalis, adult.
卵、毛毛蟲、蛹、成蟲。
The caterpillar eats毛毛蟲負責吃
It grows by shedding its skin.
靠蛻皮長大。
The chrysalis rebuilds蛹負責重建
The old body is broken down, and a new one is built.
舊的身體拆掉，蓋出新的。
The butterfly flies and lays eggs蝴蝶負責飛和產卵
It does not grow any more.
牠不會再長大。
An Observer's Code · 觀察守則
Watching without harming 觀察，但不傷害
- Do not touch hairy caterpillars. Some have hairs that can irritate the skin.不要摸有毛的毛毛蟲，有些種類的毛會讓皮膚發癢、紅腫。
- Never pull open a chrysalis or help a butterfly out of it. It needs to do this by itself.不要把蛹剝開，也不要「幫」蝴蝶出來；牠必須靠自己完成。
- If you raise a caterpillar, feed it leaves from the plant you found it on, and let the adult go where you found it.如果要養毛毛蟲，請餵牠原本所在的那種植物的葉子；羽化以後，在發現牠的地方把成蟲放走。
Classroom Activity 1 · 課堂活動一
A Life Cycle Wheel 生命週期轉盤
You need · 準備材料
- Two paper plates, a paper fastener, scissors, and colored pencils兩個紙盤、一個雙腳釘、剪刀和色鉛筆
- A ruler一把尺
Steps · 步驟
- Divide one plate into four equal parts. Draw one stage in each part, in order around the plate: egg, caterpillar, chrysalis, butterfly.把一個紙盤分成四等份，照順序繞著盤子，每一格畫一個階段：卵、毛毛蟲、蛹、蝴蝶。
- Cut one quarter out of the second plate to make a window.把第二個紙盤剪掉四分之一，做成一個窗口。
- Fix the second plate on top of the first with the fastener through the middle.用雙腳釘穿過中心，把第二個盤子固定在第一個上面。
- Turn the top plate, and tell the story of each stage as it appears. What is the animal's job at this stage?轉動上面的盤子，每出現一個階段就講一講它的故事：這個階段，牠的工作是什麼？
Make a second wheel for a grasshopper, with three parts. Put the two side by side and explain the difference to someone at home.
再替蝗蟲做一個三等份的轉盤。把兩個擺在一起，把它們的差別講給家人聽。
Classroom Activity 2 · 課堂活動二
The Leaf Detective 葉子偵探
You need · 準備材料
- A notebook, a pencil, and a magnifying glass一本筆記本、一支鉛筆和一支放大鏡
- A garden, a park, or a row of plants at school一座花園、公園，或學校裡的一排植物
Steps · 步驟
- Look for leaves with holes or chewed edges. Something has been eating here.找找有洞或邊緣被啃過的葉子。有東西在這裡吃過飯。
- Check the underside of the leaf and the stems nearby, without picking anything.看看葉子的背面和附近的莖，什麼都不要摘。
- Draw what you find: eggs, a caterpillar, droppings, an empty skin, or a chrysalis.把找到的東西畫下來：卵、毛毛蟲、糞便、蛻下來的空皮，或是蛹。
- Go back to the same plant a week later. What has changed?一個星期後回到同一株植物。有什麼不一樣了？
Many caterpillars eat only one kind of plant, so the plant is a clue to which butterfly it will be.
很多毛毛蟲只吃一種植物，所以從植物就能推測牠會變成哪一種蝴蝶。
Sources · 資料出處
Facts and numbers on this page were checked against these sources (October 2026). · 本頁的事實與數字依下列資料查證（2026 年 10 月）。
- Complete metamorphosis has four life stages: egg, larva, pupa, and adult; it is found in beetles, flies, ants, bees, wasps, butterflies, and moths; in some species it minimizes competition between larvae and adults by separating their ecological niches完全變態有四個生命階段：卵、幼蟲、蛹、成蟲；甲蟲、蠅類、蟻、蜂、蝶與蛾都屬於這一類；在某些物種，它讓幼蟲與成蟲的生態區位分開，減少彼此的競爭Wikipedia, “Holometabolism” ↗
- Partial metamorphosis has three stages: egg, nymph, and adult; the nymph resembles the adult but lacks wings; this group includes cicadas, grasshoppers, and dragonflies不完全變態有三個階段：卵、若蟲、成蟲；若蟲像成蟲但沒有翅膀；蟬、蝗蟲、蜻蜓都屬於這一類Wikipedia, “Hemimetabolism” ↗
- During the pupal stage the adult structures are formed while the larval structures are broken down; the adult structures grow from imaginal discs; the pupa of a butterfly is called a chrysalis蛹期間，幼蟲的構造被分解，成蟲的構造形成；成蟲的構造由成蟲盤長出；蝴蝶的蛹稱為 chrysalisWikipedia, “Pupa” ↗
- Inside the larva there are pairs of imaginal discs that will form the wings, legs, antennae, and other structures of the adult幼蟲體內有成對的成蟲盤，將來形成成蟲的翅、足、觸角等構造Wikipedia, “Imaginal disc” ↗
- When metamorphosis is complete, the pupal skin splits, the adult climbs out, expands its wings to dry, and flies off; the butterfly's pupa is not wrapped in a cocoon; the adult's mouthparts form a tubular proboscis變態完成後蛹皮裂開，成蟲爬出、展開翅膀晾乾後飛走；蝴蝶的蛹不包在繭裡；成蟲的口器是一根管狀的口吻Wikipedia, “Butterfly” ↗
- Caterpillars have soft bodies that grow rapidly between molts; they range from 1 mm to 14 cm in length毛毛蟲身體柔軟，在兩次蛻皮之間快速成長；體長從 1 毫米到 14 公分Wikipedia, “Caterpillar” ↗
- The monarch caterpillar has five stages, molting at the end of each; the adult emerges from the chrysalis after about two weeks帝王斑蝶的幼蟲有五齡，每一齡結束時蛻皮；成蟲約兩週後從蛹羽化Wikipedia, “Monarch butterfly” ↗
- Maria Sibylla Merian (1647–1717) documented insects directly; her work established that insects have a life cycle and do not appear by spontaneous generation梅里安（1647–1717）直接觀察並記錄昆蟲；她的工作確立了昆蟲有生命週期，而不是自然發生的Wikipedia, “Maria Sibylla Merian” ↗
- According to research from 2008, the adult tobacco hornworm moth can retain behavior learned as a caterpillar2008 年的研究指出，菸草天蛾的成蟲能保留幼蟲時期學到的行為Wikipedia, “Metamorphosis” ↗
- The silkworm prefers white mulberry leaves; after molting four times it encloses itself in a cocoon of raw silk and becomes a pupa inside家蠶偏好白桑的葉子；蛻皮四次後吐絲結繭，在繭內化蛹Wikipedia, “Bombyx mori” ↗
- Dragonfly nymphs are aquatic蜻蜓的若蟲（水蠆）生活在水裡Wikipedia, “Dragonfly” ↗
- Cicada nymphs live underground, and leave their shed skins behind when they emerge蟬的若蟲生活在地下，羽化時留下蛻殼Wikipedia, “Cicada” ↗
- A purple butterfly valley is not a place name but the gathering of several kinds of milkweed butterflies to pass the winter; Taiwan has more than 30 such valleys, and Maolin has at least 10, with four kinds of purple crow butterfly「紫蝶幽谷」不是地名，而是多種斑蝶群聚越冬的生態現象；台灣有超過 30 處紫蝶幽谷，茂林區至少有 10 處，谷內有四種紫斑蝶交通部觀光署茂林國家風景區管理處 紫蝶生態網〈何謂紫蝶幽谷〉 Maolin National Scenic Area Administration, Taiwan ↗
- The butterflies' route north runs from Maolin through Tainan, Chiayi, Yunlin, Bagua Mountain in Changhua, and Dadu Mountain in Taichung to the coast of Miaoli紫斑蝶北返的蝶道從茂林出發，經台南、嘉義、雲林林內、彰化八卦山、台中大肚山，到苗栗竹南海邊交通部觀光署茂林國家風景區管理處 紫蝶生態網 Maolin National Scenic Area Administration, Taiwan ↗