Scientists Spy Rare Carpet Of Crabs Swarming Across Deep Sea Floor

While diving in a manned submersible off the coast of Panama, scientists witnessed something you might expect to see on an anthill or beehive -- or maybe in a low-budget horror film.

"There was this turbid layer, and you couldn't see a thing beyond it. We just saw this cloud but had no idea what was causing it," Jesús Pineda, a biologist at Woods Hole Oceanographic Institution, said in a statement. "As we slowly moved down to the bottom of the seafloor, all of the sudden we saw these things."