High up on Mount Rainier in Washington, there's a stunning view of the other white-capped peaks in the Cascade Range. But Scott Hotaling is looking down toward his feet, studying the snow-covered ground.
"It's happening," he says, gesturing across Paradise Glacier.
Small black flecks suddenly appear on the previously blank expanse of white. The glacier's surface quickly transforms as more and more tiny black creatures emerge. The ice worms have returned, snaking in between ice crystals and shimmering in the sun.