Herders tether yaks before sundown. [Photo by Erik Nilsson and Tseringbum/China Daily]

"I can only communicate with livestock. I'm like the animals I herd. If I were in the city, I couldn't find the restroom or the hospital," he says.

"My kids will have knowledge even if they don't get jobs. That matters most."

Two of his six sons have gone beyond receiving education to becoming educators. They teach at nearby Dongfeng township's primary school.

Tseringbum advised the younger instructors: "You're not just teachers. You're students of your students."

But Dub explains two of his adult children had to stay home to herd rather than further their studies.

It's too much for him and his wife to care for 400 sheep and 150 yaks. (Most aren't theirs.)

"We have no choice," he explains.

The family brings in 50,000 yuan ($7,650) a year from livestock and caterpillar fungus, a parasite that grows in ghost moth larvae that's a traditional cure-all in Tibetan and Chinese medicine.

After milking the yaks the next morning, I collected dung, which is used for heating and cooking in the frigid highlands.

I'd believed nomads harvested dried droppings since that's what they burn.

Turns out, the fresher the better, since they're stacked to form walls that sheath dwellings.

The moistness makes them like mortar.