Maybe a tickle on your scalp.

或許是頭皮會癢癢的。

It's head lice.

那可能就是頭蝨了。

Tiny and tenacious.

微小又堅韌。

Thanks to millions of years of evolution, these suckers are not easy to get rid of.

經過了數百萬年的進化，這些混蛋可難除掉了。

You might end up in a salon, but not the kind for haircuts.

你最後可能會到髮廊去，但可不是去剪頭髮。

Young lice are so small they're almost impossible to see with the naked eye.

頭蝨幼蟲非常小隻，用肉眼幾乎看不到。

Our scalp is their buffet.

我們的頭皮就是他們的自助大餐。

They feed on our blood.

牠們以我們的血液維生。

You can see it inside this adult louse.

你可以從這隻成年蝨子的身體裡看出來。

It's the brownish stuff that's moving.

那棕色在動的東西就是我們的血。

The secret to their success?

牠們成功的秘訣是？

Their claws, called tarsal claws, and this little part, called a spine.

就是牠們的爪子，叫做跗骨爪，而這個小部分，稱作脊刺。

A pair on each of its six legs.

六隻腳上都各有一對。

They've evolved to fit perfectly around a human hair.

它們已經進化到可以完美抓緊人類的頭髮。

They make lice into speedy little acrobats, using our hair like a tightrope.

這爪子讓蝨子變成敏捷的雜技演員，把我們的頭髮當成鋼索。

They can't jump or fly, but they get around.

牠們不會跳也不會飛，但牠們還是到處跑。

Say two kids, one blonde, one brunette, touch heads.

假設兩個孩子，一個金髮、一個棕髮，他們頭碰頭。

The louse just scoots right over.

蝨子馬上就抓緊機會溜過去了。

It's been one long game of hopscotch, from human head to human head.

這就像是玩不完的跳格子遊戲，只是是從一個人的頭跳到另一個人的頭。

And it has to be us.

而且還一定得是人類。

Our head lice can't live on other animals.

我們的頭蝨無法在別種動物上生存。

In fact, other primates have their own species of lice, adapted to their unique hair.

事實上，其他的靈長類也有專屬的蝨子，各自為動物特殊的毛髮進化。

And birds have lice that hide in their feathers.

鳥類也有蝨子會躲在牠們的羽毛裡。

Ooh.

噢。

Cozy.

舒適。

And we all want them gone.

而我們都想要蝨子消失。

Common insecticides won't kill our head lice anymore.

一般的殺蟲劑已經殺不死牠們了。

They've become resistant to them.

牠們已經免疫了。

Even their eggs have serious staying power, glued to individual strands of hair.

連牠們的卵都有堅強的能力，可以緊緊黏在頭髮上。

But lice do have a weakness.

但蝨子並不是沒有弱點。

They can't survive away from our moist, warm scalp.

牠們少了我們濕潤、溫暖的頭皮就活不下去了。

Head lice cannot even live on other hairy parts of our body.

頭蝨甚至也無法在人類其他毛絨絨的部位生存。

So if you, or a professional, painstakingly comb them out, they'll starve, and die within hours.

如果你，或請一個專家，不辭辛勞地將牠們一隻一隻梳出來，牠們幾小時內就會餓死。

Okay, it's not fun.

好吧，這不有趣。

But it's just a temporary encounter with a tiny hitchhiker that is biologically destined just for you.

這只是一場和搭便車的小東西的短暫邂逅，而以生物學來說，牠是為了你而存在的。

Anyone else feeling itchy?

頭開始癢了嗎？

Here at Deep Look we think all critters, even the less lovable ones, like mosquitoes and ticks, deserve their moment in the spotlight.

在 Deep Look 頻道，我們認為所有生物，就算是人人喊打的，如蚊子與蝨子，也值得在鎂光燈下發光發熱。

You agree, right?

你也同意吧？

So support us on Patreon.

那就在 Patreon 上支持我們。

Click that link in the description.

點下敘述欄的連結。

Thanks!

謝啦！