You might not have known this
but ancient Egypt was an itchy place to live.
Lice were rampant.
Cleopatra for example was buried with solid gold lice combs,
while other Egyptians would shave their entire bodies
to try and get rid of the parasites.
It’s a problem we’ve had for a while,
and we probably won’t be solving it anytime soon.
Humans and lice have been living together
for about seven million years,
when our ancestors first split from chimps,
and we’ve been itching to get rid of them ever since.
There are 532 species of lice out there,
but let’s take a look at the most common type that plagues humans:
For starters, they have six legs,
and each one has a tiny hook at the end
that helps them climb from one head to the other,
latch onto your hair,
and quickly crawl down to your scalp
where they’ll feast on your blood several times a day.
And once they’ve made themselves comfortable,
lice are tricky to spot.
Adult lice, for example, are about as large as a sesame seed.
While baby lice or nymphs are a fraction of that size.
Lice are well camouflaged, too,
matching the color of the hair around them.
Not to mention your scalp is the perfect breeding ground.
In one day, a female louse can lay up to eight eggs.
Those eggs only take about a week to hatch.
Once they’re 10 days old, they’ll start laying eggs of their own.
While it’s rare to find more
than 20 live lice on any head,
there could be dozens or even hundreds of dead bodies
lingering on your scalp.
Are you feeling itchy yet?
Perhaps even worse is that they’re a pain to get rid of.
Lice can hold their breath for eight hours.
So they’ll be fine when you go take a shower
or go for a swim.
They’re also notorious for developing resistance to insecticides.
During World War II for example, militaries dusted millions
of Europeans with DDT to control lice-borne typhus.
And thanks to our overuse of it,
lice grew resistance to the poison.
Even today, we’re still seeingthe repercussions from it.
Many over-the-counter shampoos and lotions use similar
killing mechanisms to DDT,
which in some places has made it easier for lice
to grow resistant to these treatments as well.
But scientists are striking back.
In the last decade, experts have developed new weapons of attack
以防最初的非处方治疗 如伊佛霉素洗液 不起作用
for when initial over-the-counter treatments don’t work–like ivermectin lotion,
which paralyzes lice by disrupting their nervous systems.
And of course, shaving your head like the Egyptians
is a cheap and surefire bet.
但是 让我们面对现实吧 我们中的大多数人不会这样做
But let’s face it, most of us probably can’t pull off that look.