you spent the last 17 years of your life

用你過去十七年時間

walking,

走路

eating,

吃東西

and sleeping

和睡覺

above a dormant army of insects.

在休眠的昆蟲大軍之上

These are the cicadas.

這些昆蟲就是蟬

Every 17 years,

每十七年時間

billions of them emerge from the ground

數十億的蟬，從地表出現

to do three things:

來做三件事

molt,

脫皮

mate,

交配

and die.

及死亡

There are fifteen different broods of cicadas out there,

當牠們從地表出現時

grouped by when they'll emerge from the ground.

被歸類為十五窩不同的蟬

Some of these broods are on a 13-year cycle,

有些蟬窩的週期為十三年

others are on a 17-year clock.

其它則為十七年

Either way, the cicadas live underground

不論何種形式，這些蟬大部分時間

for most of their lives,

都住在地底下

feeding on the juices of plant roots.

食用植物根部的液體

When it's time to emerge,

當該露面的時候

the adults will begin to burrow their way

成蟬就開始挖掘

out of the ground

離開地底的通道

and up to the surface,

直到地面

where they will live for just a few weeks.

牠們只會待上幾個禮拜

During these weeks, though,

而這段期間裡

everybody will know the cicadas have arrived.

每個人都知道蟬已到來

There will be billions of them,

其數量高達數十億

and they're loud.

且聲響驚人

Male cicadas band together

雄蟬會一起行動

to call for female mates,

邀請雌蟬

and their collective chorus can reach

牠們集體行動的聲響

up to 100 decibels,

可達到近一百分貝

as loud as a chain saw.

和鏈鋸聲響一般

In fact, if you happen to be using a chain saw

事實上，如果你恰巧用上了鏈鋸

or a lawn mower,

或割草機

male cicadas will flock to you,

成群公蟬就會飛向你

thinking that you're one of them.

認為你是牠們其中一員

Now, like most things in nature,

如同自然定律

the cicadas don't arrive without a posse.

牠們不會單獨行動

There are all sort of awesome and gross predators and parasites

因為有各種可怕又噁心的 掠食者及寄生蟲

that come along with the buzzing bugs.

伴隨牠們而來

Take the fungus massospora for example.

以寄生菌 massospora 為例

This little white fungus buries itself

這白色小菌種將自己隱藏

in the cicada's abdomen and eats the bug alive,

在蟬的下腹中，侵蝕蟬肚

leaving behind its spores.

並將種子留下

When those spores rupture,

當這些種子破裂時

they burst out of the still-alive cicada,

牠們從仍活著的蟬腹中噴出

turning the bug into a flying salt shaker of death,

讓蟬的下腹如鹽巴揮灑 斷裂開而死亡

raining spores down upon

並將種子灑落

its unsuspecting cicada neighbors.

在未加思索的隔壁蟬身上

But while we know pretty precisely

雖然我們清楚的了解

when the cicadas will arrive and fade away,

這些蟬會來到繼而死亡

we're still not totally certain of why.

但仍不完全確定為什麼

There are certain advantages

當然囉！讓整個物種同時出現

to having your entire species emerge at once, of course.

有一定的好處

The sheer number of cicadas coming out of the ground

數量龐大的蟬從地下而來

is so overwhelming to predators,

對掠食者而言聲勢浩大

it is essentially guaranteed

實質上能保證的是

that a few bugs will survive and reproduce.

少數蟲子能存活、繁衍下一代

And since cicadas emerge every 13 or 17 years,

由於蟬每十三或十七年才出現

longer than the lifespan of many of their predators,

壽命比起很多牠們的掠食者都要長

the animals that eat them

捕食蟬的動物都

don't learn to depend on their availability.

不會依賴牠們的存在

But why 13 and 17 years

該想想為何是十三和十七年

instead of 16,

而不是十六

or 18,

十八

or 12?

或十二年

Well, that part no one really knows.

沒有人真正知道答案

It's possible the number just happened by chance,

這個數字很有可能只是碰巧發生了

or, perhaps, cicadas really love prime numbers.

或許蟬很喜愛質數

Eventually, the cicadas will mate and slowly die off,

牠們最後會交配並慢慢死亡

their call fading into the distance.

蟬鳴消逝於遠處

The eggs that they lay will begin the cycle again,

牠們下的蛋會再度延續生命

their cicada babies burrowing into the earth,

蟬寶寶在地表洞穴裡

feeding on plant juice,

以植物汁液為食

and waiting for their turn

等待牠們的時刻

to darken the skies

來染黑天際

and fill the air with their songs.

並賦予美妙的歌聲

In 17 years, they'll be ready.

牠們用十七年時間準備

Will you?

你呢？