Knives Made of Frozen Feces Are Kinda Crappy

Famed anthropologist Wade Davis inadvertently created an academic urban legend with his account of an elderly Inuit man in the 1950s who fashioned a knife out of his own frozen feces and vanished into the Arctic. That’s the conclusion of a new study by experimental anthropologists at Kent State University, who fashioned their own blades out of frozen feces—for science!—and tested them on pig hide, muscle, and tendon under ideal conditions. The knives failed every test.


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As Davis recounted in his 1998 book, Shadows in the Sun, the Inuit man’s family had taken away his tools in a vain attempt to persuade him to leave the ice and join them in a settlement. Undeterred, the man “stepped out of the igloo, defecated, and honed the feces into a frozen blade, which he sharpened with a spray of saliva,” Davis wrote. “With the knife he killed a dog. Using its rib cage as a sled and its hide to harness another dog, he disappeared into the darkness.”

Davis acknowledged that the story could be apocryphal; his source was the grandson of the man in question. But there is a similar, credible account from the same time period by Danish arctic explorer Peter Freuchen, who fashioned a chisel out of his own excrement when he found himself trapped in a pit of hardened snow.

A story this good naturally spread like wildfire, not just in the academic literature, but in popular culture as well. Kent State anthropologist Metin Eren first heard it as a teenager. “It’s one of the reasons I went into anthropology,” he admitted. Now he runs a cutting-edge lab devoted to “experimental archaeology”: recreating historical tools and other artifacts and testing them to see how well they work. There are pottery and woodworking studios, a ballistics range to shoot replica arrows, metalworking facilities, and so forth. “Basically we can make any artifact from the last 3 million years of human technology,” said Eren.

Discouraged by the current era of fake news and alternative facts, Eren was inspired to recreate the frozen fecal knife from Wade’s famous account as a way to illustrate the importance of data and scientific testing. He and his colleague, Michelle Bebber, decided to use their own feces for the experiments, rather than foisting the burden on some lowly graduate student. For eight days, Eren followed a diet rich in meats and fats, typical of what an Arctic diet would be: beef, turkey, salmon, perch, meatballs, sausages, salami, eggs, and the like.

“It was tougher than I thought having that much protein and so many fatty acids exclusively,” he said. Meanwhile, Bebber kept to her typical Western diet as a control: yogurt, lentils and rice, cheeseburgers, bagels and cream cheese, spaghetti, and so forth. Then they each collected and froze their feces whenever they had bowel movements.

“It’s funny, because we’ve got this amazing lab,” said Eren, but for that week, “I’m not in the lab—I’m in my house pooping in a bag, making knives out of my own feces. It was sort of depressing.”

They crafted the fecal knives using ceramic molds or simply using their hands to mold the feces into a rudimentary blade before sharpening them with a metal file after they were frozen solid. Then it was time to test them.

There was no need to actually butcher a dog. Eren and Bebber used pig hide—cold and hairless—muscle, and tendons. The meat they used had been refrigerated, unlike a fresh kill, which would have been warm, and the knives were chilled in dry ice to -50 C (-58 F) prior to cutting. “We really wanted to give our knives the best possible chance to succeed,” added Eren.


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Unfortunately, even under these ideal lab conditions, none of the molded or hand-shaped fecal knives made from either scientist’s feces succeeded in cutting through the hide. The knives simply melted upon contact, leaving behind brown streaks (skid marks) of melted poop. They did manage to make shallow slices on the subcutaneous fat on the underside of the hide, but the knife-edge still melted quickly and became unusable.

“I was amazed that human feces could get as hard as they do when frozen,” Eren said. “So I was thinking to myself, ‘My god, this may actually work.’ That made it all the more disheartening when we did the test.”

social experiment by Livio Acerbo #greengroundit #wired