4 Caterpillars eat so much

What is a life cycle? A life cycle is a series of changes that happens to every living thing. It starts from the moment an egg is fertilized and goes on until death. Not all life cycles are the same, but they often follow the same sort of pattern. What is the first step in a life cycle? The first step in a life cycle is usually when an egg is fertilized. Two adults of the same species mate and produce young. In butterflies, the young start out as tiny eggs. A caterpillar grows inside each egg until it is ready to hatch. The caterpillar of the monarch butterfly eats a plant called mdk-weed. If it eats enough, it can get about 2,000 times heavier in just two weeks! Most female insects lay between 100 and 200 eggs in their lifetime, but queen termites can lay up to 30,000 eggs in a single day Eggs-traordinary! Why do caterpillars eat so much? When a caterpillar hatches, it eats leaves until it is as big as it can grow. Then it makes a hard case, or pupa, around its body. The caterpillar changes into a butterfly inside this case. How does a butterfly get out? The pupa splits so the butterfly can crawl out. It pumps blood into its crumpled wings to open them out, then it sits in the sun until they are dry. The adult butterfly then flies off to find a mate and start a new life cycle. Each life cycle ends when the adult creature dies. But if the creature leaves behind young, a new cycle of life begins.

什么是生命周期？生命周期是发生在每个生物身上的一系列变化。 它从卵子受精的那一刻开始，一直持续到死亡。 并非所有的生命周期都是相同的，但它们通常遵循相同的模式。 生命周期的第一步是什么？ 生命周期的第一步通常是卵子受精的时候。 同一物种的两只成虫交配并繁殖后代。 在蝴蝶中，幼体从很小的卵开始。 毛毛虫在每个蛋里生长，直到准备孵化。 黑脉金斑蝶的毛虫吃一种叫做mdk-weed的植物。 如果它吃得足够多，它可以在短短两周内体重增加2000倍！大多数雌性昆虫一生中产100到200个卵，但蚁后白蚁一天能产3万个卵——很不寻常！毛毛虫为什么吃这么多？ 当毛毛虫孵化时，它吃树叶，直到它能长到最大。 然后，它会在身体周围形成一个坚硬的外壳或蛹。 毛毛虫在箱子里变成了蝴蝶。 蝴蝶是怎么出来的？ 蛹裂开，这样蝴蝶就可以爬出来了。 它将血液注入皱巴巴的翅膀，张开翅膀，然后坐在阳光下，直到翅膀变干。 然后，成年蝴蝶飞走寻找配偶，开始新的生命周期。 每个生命周期在成年生物死亡时结束。 但如果这种生物留下了幼崽，新的生命周期就开始了。

Do all living things reproduce? Yes, living things have young to make sure that their species survives. A female pig can have up to 12 babies at a me. When the piglets have grown into adults, they will have babies of their own. Why do animals have two parents? Most animals, including mammals and birds, have two parents, a male and a female. When they breed, they pass on chemical instructions called genes. Genes control the way a new animal looks, and the way its body works. Which living thing splits in two? Amoebas are shapeless blobs that live in water. They are tiny living things that are made up of only one cell the building blocks that make up every Like bacteria, amoebas reproduce by splitting themselves in two. Bacteria can split apart and make millions of young in just a few hours. Some bacteria are harmless, but others can cause infections in people. Mayflies live life in the fast lane! Some live for just a few hours as an adult, and must find a mate before they die. Mice and other rodents breed very quickly. A pair of house mice can produce 14 litters, or sets of babies, in just one year!

所有的生物都繁殖吗？ 是的，生物有后代来确保物种的生存。 一头母猪一次最多可以生12只小猪。 当小猪长大成人后，它们就会有自己的宝宝。 为什么动物有两个父母？ 大多数动物，包括哺乳动物和鸟类，都有双亲，一公一母。 当它们繁殖时，它们传递被称为基因的化学指令。 基因控制着一种新动物的外观和身体的运作方式。 哪种生物会一分为二？ 变形虫是生活在水中的无形状的斑点。 它们是一种微小的生物，只由一个细胞组成，这个细胞构成了所有的细胞。像细菌一样，变形虫通过将自己一分为二来繁殖。 细菌可以在几个小时内分裂并产生数百万个新细菌。 有些细菌是无害的，但有些细菌会引起人体感染。 蜉蝣生活在快车道上！有些成年后只能活几个小时，必须在死前找到配偶。 老鼠和其他啮齿动物繁殖得很快。 一对家鼠在一年之内就能产下14窝幼鼠。

Why do turtles have lots of babies? Some animals have lots of babies to make sure at least some survive. Hundreds of baby hatch at the same time and head for the sea. Gulls and lizards eat some of them, but because there are so many turtles, a large number will survive. Do any animals have just one baby? Yes, orang-utans have one baby at a time. This gives the mother more time to feed and look after the baby, and keep it safe. The baby grows quite slowly, but learns how to survive. This increases its chances of becoming an adult. Do mums and dads get help? Sometimes, yes. Bee-eaters are birds that eat bees and other insects. Bee—eater parents can't carry enough food to feed all their babies, so their older children help them out. Humans usually give birth to one child at a time, but sometimes more. Very rarely, a woman gives birth to seven or even eight babies at once!

为什么海龟有很多宝宝？ 有些动物会生很多孩子，以确保至少有一些能存活下来。 数百只幼崽同时孵化并向大海进发。 海鸥和蜥蜴吃掉了其中的一些，但因为有这么多的海龟，大量的海龟将存活下来。 有动物只生一个孩子吗？ 是的，猩猩一次只生一个宝宝。 这给了妈妈更多的时间来喂养和照顾宝宝，并保证它的安全。 婴儿成长得很慢，但学会了如何生存。 这增加了它成为成年人的机会。 妈妈和爸爸会得到帮助吗？ 有时,是的。食蜂鸟是一种以蜜蜂和其他昆虫为食的鸟类。 吃蜂的父母不能携带足够的食物来喂养他们所有的孩子，所以他们的大孩子帮助他们。 人类通常一次只生一个孩子，但有时会生更多。 一个女人一次生七个甚至八个孩子的情况非常罕见！

Do plants have babies? Most plants produce seeds that grow into new plants. Flowering plants produce seeds when they are fertilized. Insects such as bees help fertilize plants by carrying pollen from one flower to another. The fertilized plant then produces its seeds. Seeds may be small, but they contain all the building blocks that a plant needs to grow. A tiny acorn can grow. into an oak tree more than 40 metres tall! Bees like to eat the dust-like pollen made by flowers. As a bee flies around, it spreads pollen from flower to flower and fertilizes the plants. Why are seeds spread? Seeds need to be spread away from a plant so that they have space to grow. When an animal eats fruit, the tough seeds pass out of the animal in its droppings. The droppings help the seed to grow into a new plant. Some seeds have spiky or sticky cases. These get stuck in an animal's fair, and are carried to new places when the animal moves around. Which plant 'runs'? Some plants can make new plants by sending out shoots. Strawberries, for example, produce shoots called runners without being fertilized. They also make flowers that are fertilized and form seeds.

植物有宝宝吗？大多数植物产生的种子会长成新的植物。 开花植物受精后产生种子。 蜜蜂等昆虫通过将花粉从一朵花传到另一朵花来帮助植物受精。 受精后的植物就会产生种子。 种子可能很小，但它们包含了植物生长所需的所有组成部分。 小橡子也能生长。撞上了一棵40多米高的橡树！蜜蜂喜欢吃花朵产生的像灰尘一样的花粉。 蜜蜂飞来飞去，把花粉从一朵花传到另一朵花，使植物受精。 为什么种子会传播？种子需要远离植物，这样它们才有生长的空间。 当动物吃水果时，坚硬的种子会随着动物的粪便排出体外。 这些粪便有助于种子长成一株新植物。 有些种子有尖的或粘的壳。 它们会被困在动物的集市上，当动物四处走动时，它们会被带到新的地方。 哪个工厂“运行”？有些植物可以通过发新芽来长出新植株。 例如，草莓在不施肥的情况下会产生一种叫做“芽”的嫩芽。 它们也会开花，受精后形成种子。

Do animals make seeds? No, animals make babies. Not all babies look like their parents. Baby insects, such as ladybird larvae often look completely different from the adults. But as they grow, they change. In time, they will mate and have babies of their own. why do birds sit on their eggs? All birds lay eggs, and most of them sit on them until they hatch. They do this because baby birds need warmth to grow. The mother is often in charge of this task, although sometimes the parents take turns. Do any mammals lay eggs? Most mammals give birth to live young, but the duck-billed platypus lays eggs. The female platypus lays two or three small eggs. The eggs hatch after about ten days. The mother feeds the babies with milk for up to five months. The platypus is a master builder. It digs tunnels in riverbanks to make safe nests. The entrances to the tunnels are often underwater. The ostrich lays the heaviest egg of any bird. Each one can weigh up to 1.3 kilograms that's more than a bag of sugar! Tadpoles look very different from adult frogs. But in just a few weeks, they grow legs and start to look like their parents.

动物会产生种子吗？不，动物会生孩子。 不是所有的婴儿都长得像他们的父母。 小昆虫，如瓢虫幼虫，通常看起来与成虫完全不同。 但随着他们的成长，他们也发生了变化。 随着时间的推移，它们会交配并生下自己的孩子。 为什么鸟要坐在它们的蛋上？ 所有的鸟都下蛋，大多数鸟都坐在蛋上直到蛋孵出来。 它们这样做是因为幼鸟需要温暖来成长。 母亲通常负责这项任务，尽管有时父母轮流。 哺乳动物会产卵吗？大多数哺乳动物都产幼崽，但鸭嘴兽产卵。 雌性鸭嘴兽产两到三个小蛋。 蛋大约十天后孵化。 母亲用牛奶喂养婴儿长达五个月。 鸭嘴兽是建筑大师。 它在河岸上挖隧道筑巢。 隧道的入口通常在水下。 鸵鸟下的蛋是所有鸟类中最重的。 每只可重达1.3公斤，比一袋糖还重！蝌蚪看起来和成年青蛙很不一样。 但在短短几周内，它们就长出了腿，开始看起来像它们的父母。

Which animal likes snorkelling? Mosquitoes lay their eggs in still water. When the young hatch, they need to breathe air, so they poke a special tube through the surface of the water. This acts like a snorkel and lets them suck in air. How long does a cicada stay young? A young cicada spends most of its life underground, feeding on plant sap. It stays like this for up to 17 years. It then crawls up a tree, sheds its skin one last time, and becomes an adult. The adult cicada lives for just a few weeks. Why does a glow-worm glow? The glow-worm is a beetle that makes a light in its body. The female has a special organ in her abdomen that gives off light. The beetle glows to signal to a male that she is nearby and ready to mate. Why do insects hide eggs? Insects hide their eggs to stop other animals eating them. Cabbage white butterflies lay their eggs on the underside of cabbage leaves. This hides the eggs and will also provide fresh leaves for the young to eat. Unlike most insects, female earwigs guard their eggs from predators until they hatch. If you threaten an elephant hawkmoth caterpillar, it will suck in air and blow up its head to make itself look too big to eat!

哪种动物喜欢浮潜？ 蚊子在静止的水中产卵。 当幼崽孵化时，它们需要呼吸空气，所以它们在水面上戳出一根特殊的管子。 这就像一个通气管，让它们吸入空气。 蝉能年轻多久？ 一只年轻的蝉一生中大部分时间都在地下度过，以植物汁液为食。 这种情况可以持续17年。 然后它爬上一棵树，最后一次蜕皮，成为一个成年人。 成年蝉只能活几个星期。 萤火虫为什么会发光？ 萤火虫是一种在体内发光的甲虫。 雌性的腹部有一个特殊的器官可以发光。 甲虫发光是向雄甲虫发出信号，表明她在附近，准备交配。 昆虫为什么要藏卵？昆虫把它们的卵藏起来以防止其他动物吃掉它们。 卷心菜白蝴蝶在卷心菜叶子的背面产卵。 这样可以把蛋藏起来，也可以为幼鸟提供新鲜的叶子。 与大多数昆虫不同，雌性地蜈蚣会保护它们的卵不受捕食者的伤害，直到它们孵化出来。 如果你威胁到一只象蛾毛虫，它会吸进空气，吹起它的头，让自己看起来大得不能吃！