and laid an egg sac.

並下了一個蛋囊。

Luckily, roaches don't go out of their way to do this,

幸運的是，蟑螂不會不顧一切地去做這件事。

so it doesn't happen very often.

所以它不經常發生。

But there are a bunch of other unsavory bugs

但還有一堆其他的不乾淨的蟲子。

that will lay eggs all over your body on purpose.

會在你身上故意下蛋的。

First up, the human botfly.

首先是人肉蝴蝶。

These insects, which are native to Central

這些昆蟲，原產於中部地區。

and South America, glue their eggs to mosquitoes

在南美洲，它們的卵被粘在蚊子上

and other blood-sucking insects.

和其他吸血昆蟲。

When the mosquito bites you, the eggs hatch.

當蚊子叮咬你的時候，卵就會孵化。

Then the larvae wriggle into your skin,

然後幼蟲就會蠕動著進入你的皮膚。

creating a painful pimple that leaks pus.

產生疼痛的痘痘，滲出膿液。

Or, as the baby botflies call it, lunch.

或者，正如小蒼蠅們所說的，午餐。

After five to 10 weeks, they escape.

5到10周後，它們就會逃跑。

Not long after that, they reach adulthood,

不久之後，他們就成年了。

ready to mate, and start the cycle all over.

準備好交配，然後重新開始循環。

Another tropical parasite is Tunga penetrans,

另一種熱帶寄生蟲是Tunga penetrans。

more commonly known as the sand flea.

更俗稱沙蚤。

Females burrow into the bottom of your foot

雌性會鑽進你的腳底下

and slurp your blood.

並啜飲你的血液。

They start off smaller than a grain of sand

它們一開始比一粒沙子還小

but grow to 2,000 times their size within a week

卻在一週內長到2,000倍大小

as they swell with your blood and up to 200 eggs.

因為它們會隨著你的血液而膨脹，最多隻能產200個卵。

Those eggs fall to the ground and hatch,

那些蛋落到地上，然後孵化。

waiting for the next bare foot to pass by.

等待下一個光腳的人經過。

But some egg-laying parasites go more than just skin deep.

但有些產卵寄生蟲不止於皮毛。

Tapeworms, for example, invade your intestines.

比如說，絛蟲會侵入你的腸道。

Adults can grow to be longer than a bowling lane

成年人可以長到比保齡球道還長。

and block up your digestive system.

並堵塞你的消化系統。

But it gets worse,

但它變得更糟。

because they lay tens of thousands of eggs,

因為它們會產下數以萬計的蛋。

which can hatch and migrate,

可以孵化和遷移。

spreading throughout your lungs,

擴散到整個肺部。

muscles, and even your brain.

肌肉，甚至你的大腦。

If that sounds gruesome, just wait till you hear

如果這聽起來很可怕，你就等著聽吧

about the Loa loa worm.

關於羅亞羅亞蟲。

It can be passed from human to human

它可以在人與人之間傳遞

by hitching a ride inside of deer flies.

通過搭上鹿飛內部。

When the flies bite you, the larvae enter through the wound.

當蒼蠅咬你的時候，幼蟲會從傷口進入。

After five months growing beneath your skin,

經過五個月在皮膚下的生長。

they reach adulthood and start to release

他們到了成年，並開始釋放

thousands of embryos a day.

每天有成千上萬的胚胎。

Sometimes you can even see the worms

有時你甚至可以看到蟲子

moving under your skin or across your eyeball.

在你的皮膚下或眼球上移動。

But, hey, not every egg-laying invader is sinister.

不過，嘿嘿，並不是每一個生蛋的入侵者都是陰險的。

Face mites, for example, are pretty innocuous.

比如說臉蟎，就很無害。

They live on pretty much everyone's face,

他們幾乎活在每個人的臉上。

and most people just never notice.

而大多數人只是從來沒有注意到。

After all, they feed on facial oil, not flesh.

畢竟，它們以面油為食，而不是肉食。

When it comes time to breed,

到了繁殖的時候。

females just lay one egg inside of your pores.

雌性只需在你的毛孔內產一個卵。

Even better, researchers can now study your face mites

更好的是，研究人員現在可以研究你臉上的蟎蟲了。

to track how your ancestors migrated across the planet,

來追蹤你的祖先是如何在地球上遷移的。

because we usually pass them from parent to child,

因為我們通常把它們從父母那裡傳給孩子。

so the mites stay in the family.

所以蟎蟲留在家裡。

But face mites aren't the only helpful bug around.

但是，臉蟎並不是唯一有用的蟲子。

Green bottle flies might be useful in medicine.

綠瓶蠅也許在醫學上有用。

They lay their eggs inside of open wounds,

它們在開放的傷口內產卵。

and then the maggots hatch and devour the damaged flesh.

然後蛆蟲孵化併吞噬受損的肉體。

That sounds brutal, but one day

聽起來很殘忍，但總有一天

we might be able to harness this process

我們或許可以利用這個過程

to treat diabetic foot ulcers

治療糖尿病足潰瘍

and other slow-healing wounds.

和其他緩慢癒合的傷口。

Because when the maggots go to town,

因為當蛆蟲進城的時候。

they actually clean the area

他們實際上是在打掃衛生

and remove a lot of the dead tissue.

並去除大量的死組織。

They even secrete proteins that reduce inflammation.

它們甚至能分泌出減少發炎的蛋白質。

So maybe botflies, fleas, and tapeworms

所以，也許肉蠅，跳蚤和絛蟲。

could learn a thing or two

可見一斑

and at least make themselves useful

至少讓自己有用

if they're going to move right in.

如果他們要移動的權利。