Some strange holes pockmark the bottom of the North Sea. They can be anywhere from a few feet to hundreds of feet wide. But all of them are about four inches deep. That doesn’t match the kinds of pits produced by geological processes or ocean currents. Instead, a recent study says they were created on porpoise.
Scientists have known about the pits for years. The most common explanation said they were produced by blobs of methane bubbling up through the sediments. But such pits are cone shaped. And wider methane pits are also deeper.
Sea otters, dolphins, crows, elephants, octopuses, crocodiles—these animals, like humans, use tools for a variety of activities, from eating and drinking, to grooming and play, to combat and communication. But far fewer animals are known to manufacture and modify the tools, rather than simply using what they come across in their environment. And now, humpback whales are part of this much smaller group of “tool wielders.”
