But when food becomes scarce,

但當食物短缺時

hungry, desperate locusts crowd onto small patches of land

飢餓絕望的蝗蟲便成群結隊

where they can still find something to eat.

群聚在還能找到食物的地方

Contact between different locusts' hind legs set off a slew of reactions

蝗蟲的後腿相互接觸聯絡 形成連鎖反應

that change their appearance and behavior.

使蝗蟲們的外表和行為改變

Now, instead of shunning their peers, they seek each other out.

牠們不再離群索居，而是團體行動

The locusts eventually start marching and then fly away in large numbers

最後集結成千萬大軍飛走

seeking a better habitat.

去尋找更好的居住地

These gigantic swarms can host millions of insects

這類大型的群聚行為 甚可包含上百萬隻昆蟲

and travel thousands of miles,

橫越數千英哩

devastating vegetation and crops.

侵略蔬果和作物

They stay close to each other, but not too close,

牠們彼此緊密靠近， 但也維持必須的距離

or they might get eaten by their hungry neighbors.

否則可能被飢餓的同類吃掉

When many individual organisms, like locusts,

當許多獨立的生物個體，例如蝗蟲、

bacteria,

細菌、

anchovies,

鯷魚、

or bats,

或蝙蝠

come together and move as one coordinated entity,

集結群聚並形成 一個和諧的整體來移動時

that's a swarm.

那就是群聚

From a handful of birds to billions of insects,

從一小群鳥乃至於數十億隻昆蟲

swarms can be almost any size.

群聚可以有各種不同大小

But what they have in common is that there's no leader.

這些群聚的共同點是 牠們都沒有領導者

Members of the swarm interact only with their nearest neighbors

群聚內的成員 僅與其左右鄰居互動交流

or through indirect cues.

或是透過間接暗示

Each individual follows simple rules:

每個個體都遵守簡單的規則：

Travel in the same direction as those around you,

跟著旁邊的同類同方向一起走、

stay close,

跟緊一點、

and avoid collisions.

但不要相撞

There are many benefits to traveling in a group like this.

這種移動方法有許多好處

Small prey may fool predators by assembling into a swarm

體型較小的獵物可藉群聚移動 來呼嚨大型掠食者

that looks like a much bigger organism.

讓牠們看起來像是更大的生物

And congregating in a large group

並聚集在一個超大團體裡

reduces the chance that any single individual will be captured.

減少了個體被掠食的機會

Moving in the same direction as your neighbors

和你的近鄰朝同一個方向移動

saves energy by sharing the effort of fighting wind or water resistance.

可共同對抗風阻或水阻以節省體力

It may even be easier to find a mate in a swarm.

在團體中找對象似乎也較容易

Swarming can also allow groups of animals

群聚的動物們

to accomplish tasks they couldn't do individually.

也能完成一些無法獨自完成的任務

When hundreds or millions or organisms follow the same simple rules,

當數百或上百萬的生物 遵從相同且簡單的規則時

sophisticated behavior called swarm intelligence may arise.

便可產生一種稱為 「群聚智力」的複雜行為

A single ant can't do much on its own,

一隻螞蟻沒辦法僅靠自己做多少事

but an ant colony can solve complex problems,

但一個蟻群可以解決很複雜的問題

like building a nest

例如建造一個巢穴

and finding the shortest path to a food source.

和尋找離食物最近的路徑

But sometimes, things can go wrong.

但有時也會出錯

In a crowd, diseases spread more easily,

在群聚中，疾病傳播容易多了

and some swarming organisms may start eating each other if food is scarce.

還有，當食物短缺時， 群聚的個體可能會吃了彼此

Even some of the benefits of swarms, like more efficient navigation,

即使群聚的優勢，像是較佳的導航力

can have catastrophic consequences.

有時也可能造成悲劇

Army ants are one example.

行軍蟻就是個例子

They lay down chemicals called pheromones

牠們會分泌一種化學物質， 稱為費洛蒙

which signal their neighbors to follow the trail.

這能讓其他行軍蟻追蹤蹤跡

This is good if the head of the group is marching towards a food source.

如果為首的行軍蟻朝著 食物的方向前進就好

But occasionally the ants in the front can veer off course.

但偶爾帶頭的行軍蟻會誤入歧途

The whole swarm can get caught in a loop following the pheromone trail

那麼跟在後面的行軍蟻 可能因此而落入無限迴圈

until they die of exhaustion.

直到體力耗竭而死

Humans are notoriously individualistic, though social, animals.

人類是惡名昭彰的個體主義者， 雖然也是社會的動物

But is there anything we can learn from collective swarm-based organization?

但我們能否從這樣的生物群聚行為中 學習到什麼呢？

When it comes to technology, the answer is definitely yes.

若是有關科技方面， 答案絕對是肯定的

Bats can teach drones how to navigate confined spaces without colliding,

運用蝙蝠的飛行技術可讓無人機 順利導航通過狹小的空間

fish can help design software for safer driving,

魚群行為可以用來 設計較安全的駕駛軟體

and insects are inspiring robot teams that can assist search and rescue missions.

昆蟲構造幫助設計 協尋和搜救的機器人團隊

For swarms of humans, it's perhaps more complicated

而就人類的群聚來說， 這也許又更複雜了

and depends on the motives and leadership.

而且會因動機和領導不同而異

Swarm behavior in human populations can sometimes manifest as a destructive mob.

人類的群聚行為 有時會變成具破壞性的暴民

But collective action can also produce a crowd-sourced scientific breakthrough

但集體行動也可以產生 科學上的突破、

an artistic expression,

藝術的表現、

or a peaceful global revolution.

或一場和平的全球革命