In Hurricane Crawl, the scientists turned over rocks until something crawled out of a pore on the underside of one. It was a dipluran—a translucent, eyeless insect with eerily long appendages that waved slowly in a headlamp’s beam. It was almost certainly a new species, never seen by humans until that moment. For the next few hours, Krejca and Despain wove their conveniently slender bodies into tiny side passages like millipedes themselves, overturning rocks and scanning walls. Little more of note emerged. The problem is, there are two miles of known human-size passages in Hurricane Crawl, but vastly more unobservable “mesocaverns”: endless small crevices and tubes with multiple layers of floor rubble. That is probably where the real action is. Krejca’s advice: If you don’t have time to leave bait—rotting shrimp and blue cheese are her favorites—just stay put and wait.
Troglobites tend to be lean, ready for action. One day in nearby Crystal Cave, members of the team crawled through a low, lifeless passage floored with sand. They came upon a single acorn, probably brought in by a pack rat, and a squirt of rodent poop. These objects had sprouted whole ecosystems: cotton candy gardens of multicolored fungus, near-microscopic springtails, detritus-eating beetles, and quarter-inch Taiyutyla and Striariidae millipedes. The innards of a see-through Striariidae told the short story of its life: The yellowish blotch in its midsection was part of its gut; the brownish stuff farther back, its latest meal. Nearby lurked tiny predators: Nesticus spiders spun slender webs, and pale, venomous centipedes peculiar to Crystal darted with startling speed. Often caves contain a weird overabundance of predators; this suggests that prey often runs out, leaving the hunters to go after anything alive or dead, including each other. Up another sandy passage in Crystal Cave, one very lost acorn had used its stored energy to sprout a six-inch, pure white tendril with minuscule leaves—its last gasp before being devoured in this alien world.
Another morning the team hopped a rushing creek and climbed up to Kaweah Cave, whose airy cliff entrance was camouflaged with buckeye trees. Krejca disappeared through a tiny hole in back, and an hour later emerged with a prize: a new species of pseudoscorpion she had just discovered under a rock 200 feet (61 meters) back. Eyeless and gray, it looked like a scorpion minus the stinging tail; these creatures inject their venom instead with their sharp claws. These were wildly outsize compared with the body, and covered with fine sensory cilia that waved independently. Krejca breathed gently on it. It ran backward, then raised its poisoned hands as if to strike. Luckily, it was no bigger than a letter on a page of National Geographic magazine.