Nature's Time Capsules

Nests built long ago by the humble pack rat provide tantalizing peeks into the earth's past

Part way up we came to a high cliff and in its face were niches . . . and in some of them we found balls of a glistening substance looking like pieces of variegated candy . . . it was evidently food of some sort, and we found it sweet but sickish, and those who were hungry, making a good meal of it, were a little troubled with nausea afterwards.

-- from the diary of a lost prospector

in the Gold Rush of 1849

Nausea? Little wonder. The glistening balls mistaken for a snack that day in Nevada were later...

Want the full story?

Subscribe Now

Subscribe
Subscribe

Get TIME the way you want it

  • One Week Digital Pass — $4.99
  • Monthly Pay-As-You-Go DIGITAL ACCESS$2.99
  • One Year ALL ACCESSJust $30!   Best Deal!
    Print Magazine + Digital Edition + Subscriber-only Content on TIME.com

Learn more about the benefits of being a TIME subscriber

If you are already a subscriber sign up — registration is free!