This story appears in the March 2017 issue of National Geographic magazine. Lice have plagued humankind throughout history. Spreading from person to person by close contact, they latch onto hair ...

It may be hard to find the lice or eggs, because there might not be that many and they’re super small. Using a magnifying glass can help, or a nurse or doctor can look for them with a microscope. You ...

We can see objects as small as 0.1 millimeters, and that means we can just about see these lice eggs in our hair ... There's three types of microscope: light, like this one here, and two types ...