WEBVTT - Stealing Sand, Communicating via Poop, and Clinical Trial Participation 0:00:00.960 --> 0:00:03.840 Welcome to How Stuff Works Now. I'm your host, Lauren Vogelbaum, 0:00:03.880 --> 0:00:10.160 a researcher and writer. Here at How Stuff Works. Every week, 0:00:10.200 --> 0:00:12.560 I'm bringing you three stories from our team about the 0:00:12.600 --> 0:00:16.560 weird and wondrous advances we've seen in science, technology, and culture. 0:00:17.200 --> 0:00:20.640 This week, sand is in such high demand and construction 0:00:20.680 --> 0:00:24.120 markets around the world that people are stealing tons of it. 0:00:24.760 --> 0:00:29.240 And unrelated, it turns out that white rhinos communicate via 0:00:29.360 --> 0:00:34.040 massive communal poop piles. But First, Senior editor Katherine Whitborren 0:00:34.200 --> 0:00:37.000 and our freelance writer Alia Hoyt take us behind the 0:00:37.040 --> 0:00:41.400 scenes of medical research. Clinical trials make amazing new treatments 0:00:41.440 --> 0:00:44.199 possible and safe, but here in the United States, they 0:00:44.200 --> 0:00:47.519 struggle to find participants. Here's why and what you can 0:00:47.520 --> 0:00:53.640 do to help. Dave Bexfield of Albuquerque, New Mexico, was 0:00:53.680 --> 0:00:57.120 diagnosed with multiple sclerosis in two thousand and six. Three 0:00:57.200 --> 0:00:59.720 years later, he applied for a clinical trial sponsored by 0:00:59.760 --> 0:01:03.360 the National Institutes of Health that involved a stem cell transplant. 0:01:03.720 --> 0:01:06.560 Bexfield says the trial saved his life. Within a few 0:01:06.560 --> 0:01:09.039 months of completion, in twenty ten, he could walk again 0:01:09.120 --> 0:01:12.920 without a cane or a walker. Participation levels in clinical 0:01:12.959 --> 0:01:16.480 trials are often very low, even for patients with terminal diseases. 0:01:16.800 --> 0:01:20.040 Doctor Julie M. Vos, immediate past president of the American 0:01:20.200 --> 0:01:23.640 Society of Clinical Oncology, told us that only about three 0:01:23.680 --> 0:01:27.560 percent of adopt patients with cancer participate in clinical trials. 0:01:28.040 --> 0:01:30.920 This low rate limits patient access to new interventions that 0:01:31.000 --> 0:01:35.440 could treat or even cure their cancer. In fact, analysis 0:01:35.480 --> 0:01:38.679 of cancer trials found that a whopping forty of them 0:01:38.720 --> 0:01:41.880 were unable to enroll the minimum number of participants. Another 0:01:41.959 --> 0:01:45.200 survey showed only thirty five percent of Americans said they 0:01:45.240 --> 0:01:48.000 were likely to enroll in a clinical trial. So why 0:01:48.120 --> 0:01:50.600 don't more people participate in trials, even if it might 0:01:50.640 --> 0:01:53.560 save their lives? Here are some reasons. Number one, they 0:01:53.560 --> 0:01:57.240 don't know what's available. People diagnosed with diseases often mistakenly 0:01:57.240 --> 0:02:00.080 assumed that their doctor will suggest appropriate clinical trials if 0:02:00.080 --> 0:02:02.880 they're out there. Although some physicians are very dialed into 0:02:02.920 --> 0:02:05.880 ongoing research, many aren't or simply don't have time to 0:02:05.920 --> 0:02:08.880 sit through all the opportunities for their patients. So in 0:02:08.919 --> 0:02:12.120 addition to asking your doctor directly about clinical studies, you 0:02:12.120 --> 0:02:14.600 can also check a number of online resources that can 0:02:14.639 --> 0:02:17.679 help you find them. The National Institute of Health website 0:02:17.919 --> 0:02:22.320 lists several databases, including clinical Trials dot gov, which allows 0:02:22.400 --> 0:02:26.200 users to search by condition or location. Breast Cancer Trials 0:02:26.240 --> 0:02:29.720 dot org is another disease specific option where you can 0:02:29.760 --> 0:02:33.000 be matched with an appropriate study. Search for finding clinical 0:02:33.040 --> 0:02:36.880 trials to learn more. Number two, the trial locations are inconvenient. 0:02:37.280 --> 0:02:40.160 Geography is a major problem with clinical trials because they 0:02:40.200 --> 0:02:43.040 tend to be in specific locations that are often not 0:02:43.120 --> 0:02:46.720 convenient to patients. Vicky Carr is our breast cancer survivor 0:02:46.760 --> 0:02:50.320 and patient advocate for Susan G. Coleman, who lives outside Washington, 0:02:50.400 --> 0:02:53.000 d C. For four years, she's taken a bus trip 0:02:53.040 --> 0:02:55.519 every four weeks for a trial that will hopefully prevent 0:02:55.560 --> 0:02:59.480 her cancer from returning and spreading. Another example, the multiple 0:02:59.520 --> 0:03:03.200 scross a study that Dave Bexfield participated in, required ten 0:03:03.280 --> 0:03:06.520 round trip flights from Albuquerque to Houston, including initial treatment 0:03:06.560 --> 0:03:09.440 and follow up trips. His cost eventually were covered by 0:03:09.440 --> 0:03:12.560 insurance company after a big fight. But not everyone has 0:03:12.560 --> 0:03:15.360 the luxury of taking so much time off work. But 0:03:15.480 --> 0:03:18.480 before you ride off a possibly life saving study, it's 0:03:18.520 --> 0:03:21.239 important to know the terms because some trials will pay 0:03:21.280 --> 0:03:25.600 for travel and hotel expenses. Number three, Patients worry about 0:03:25.600 --> 0:03:28.240 getting the placebo. A lot of people are afraid of 0:03:28.280 --> 0:03:30.680 going through all that trouble of participating in a trial 0:03:30.960 --> 0:03:32.519 to only wind up in the group that gets the 0:03:32.560 --> 0:03:35.520 sugar pill instead of the drug. But nowadays trials are 0:03:35.520 --> 0:03:38.600 designed to be more patient friendly. For instance, there might 0:03:38.600 --> 0:03:41.520 be several treatment groups and a single placebo group, so 0:03:41.560 --> 0:03:44.040 the chances of receiving the placebo may only be twenty 0:03:44.040 --> 0:03:48.040 five to thirty three percent. Crossover designs also allow every 0:03:48.040 --> 0:03:50.880 participant to receive the drug at some point during the trial. 0:03:51.160 --> 0:03:54.440 Another incentive is the open label extension trial. This is 0:03:54.480 --> 0:03:57.280 a special trial that allows participants who complete the main 0:03:57.320 --> 0:03:59.680 trial to have guaranteed access to the drug at the 0:03:59.760 --> 0:04:02.680 end of it. Also, in the case of cancer trials, 0:04:02.840 --> 0:04:05.160 people in either group will get at least the current 0:04:05.240 --> 0:04:08.400 standard of care for their condition. No one goes without treatment. 0:04:08.960 --> 0:04:13.000 Number four reason Patients also worry about safety. They hear 0:04:13.040 --> 0:04:15.520 the word clinical trial and figure that the drug being 0:04:15.560 --> 0:04:18.200 tested could really harm them, But by the time it 0:04:18.240 --> 0:04:20.440 gets to the stage of being tested on humans, the 0:04:20.480 --> 0:04:22.880 researchers have already tested this out on cells grown in 0:04:22.880 --> 0:04:25.600 a lab, as well as on animals. These are called 0:04:25.760 --> 0:04:30.320 preclinical studies. Clinical trials are done only after preclinical studies 0:04:30.320 --> 0:04:32.680 suggest that the treatment is likely to be safe and 0:04:32.680 --> 0:04:35.719 will work in people. The research must also be approved 0:04:35.720 --> 0:04:38.919 by the u S Food and Drug Administration. The researchers 0:04:38.920 --> 0:04:41.440 and doctors we spoke with for this story emphasize the 0:04:41.480 --> 0:04:44.440 need to have a wider pool of study subjects. Clinical 0:04:44.480 --> 0:04:47.200 trials need both men and women of all races and 0:04:47.360 --> 0:04:50.560 ages to be sure that a treatment will work on everyone. 0:04:50.760 --> 0:04:52.440 And by the way, you don't have to be sick 0:04:52.480 --> 0:04:55.120 to participate in a clinical trial. Lots of them are 0:04:55.160 --> 0:05:02.400 looking for healthy volunteers. Next up, staff writer Joe McCormick, 0:05:02.520 --> 0:05:04.760 who's also the co host of a podcast you might 0:05:04.800 --> 0:05:07.120 have heard of called Stuff to Blow Your Mind, presents 0:05:07.120 --> 0:05:10.120 a story from our freelancer Dave Ruse about the strange 0:05:10.200 --> 0:05:18.840 and very serious world of the sand mafia. As strange 0:05:18.880 --> 0:05:21.679 as it may sound, sand is one of the world's 0:05:21.720 --> 0:05:26.800 hottest commodities. The global construction boom has created an insatiable 0:05:26.839 --> 0:05:31.240 appetite for sand, the chief ingredient in making concrete. The 0:05:31.279 --> 0:05:34.279 problem is that sand isn't as abundant as it used 0:05:34.320 --> 0:05:37.920 to be, and when high demand and high value. Meet scarcity, 0:05:38.240 --> 0:05:42.760 you open the doors to smuggling. Meet the sand mafia. 0:05:43.760 --> 0:05:48.320 In India, illegal sand mining is the country's largest organized 0:05:48.320 --> 0:05:53.719 criminal activity. In inland villages, armed sand mafia's steel land 0:05:53.839 --> 0:05:56.560 in order to strip its top soil and extract the 0:05:56.600 --> 0:06:01.480 layers of valuable sand beneath along the posts. Pirate dredging 0:06:01.560 --> 0:06:05.160 vessels siphon sand from the seafloor in broad daylight, with 0:06:05.240 --> 0:06:09.760 bribed officials turning a blind eye. The Pilford sand fetches 0:06:09.800 --> 0:06:12.160 a good price on the black market, where it is 0:06:12.240 --> 0:06:15.960 sold to construction companies building high rises in mega cities 0:06:16.000 --> 0:06:20.479 like Mumbai. According to journalist Vince Bisser, who wrote about 0:06:20.520 --> 0:06:23.520 sand theft for Wired and The New York Times, people 0:06:23.520 --> 0:06:27.720 who resist the mafia are beaten or killed, including police officers. 0:06:28.560 --> 0:06:32.880 Filmmaker Dennis Dellastroc witnessed similar tactics in Morocco while shooting 0:06:33.000 --> 0:06:36.800 Sand Wars, a documentary about the global sand trade and 0:06:36.920 --> 0:06:41.520 its environmental impact. According to Dellastrac, quote, the sand of 0:06:41.560 --> 0:06:45.360 mafia in Morocco is the second most powerful criminal organization 0:06:45.440 --> 0:06:48.839 in the country. We saw people with shovels taking every 0:06:48.920 --> 0:06:51.920 last grain of sand from the beach where a few 0:06:52.040 --> 0:06:54.400 years ago you used to have a very thick and 0:06:54.480 --> 0:06:58.800 white beach. Now you have this lunar landscape. It's devastating. 0:07:00.160 --> 0:07:04.200 Environmental officials estimate that half of Morocco's construction sector is 0:07:04.200 --> 0:07:08.600 built with stolen sand. The irony, says Dellastroc, is that 0:07:08.680 --> 0:07:11.160 much of the stolen sand is used to build housing 0:07:11.200 --> 0:07:14.720 for foreign tourists who are flocking to Morocco precisely because 0:07:14.760 --> 0:07:18.680 of its beaches. If both legal and illegal sand mining 0:07:18.720 --> 0:07:22.160 persists at its current rate in places like Morocco, India, 0:07:22.400 --> 0:07:26.400 and across Asia, there may be few beaches left. The 0:07:26.520 --> 0:07:31.240 United Nations Environment Program reported in that quote, sand and 0:07:31.280 --> 0:07:34.960 gravel represent the highest volume of raw material used on 0:07:35.040 --> 0:07:39.800 Earth after water. Their use greatly exceeds natural renewal rates. 0:07:40.400 --> 0:07:44.239 Dellastrac claims that eight of everything built on our planet 0:07:44.320 --> 0:07:47.760 is built out of concrete, and concrete uses a whole 0:07:47.800 --> 0:07:51.240 lot of sand. It takes thirty thousand tons or more 0:07:51.240 --> 0:07:54.720 than twenty seven thousand metric tons of sand to construct 0:07:54.800 --> 0:07:58.600 one kilometer of highway. It takes about two hundred tons 0:07:58.680 --> 0:08:00.760 or about a hundred and eighty men trick tons to 0:08:00.800 --> 0:08:05.440 build the average concrete house. Reports Coastal Care, a nonprofit 0:08:05.480 --> 0:08:10.200 foundation dedicated to beach conservation. According to a report from 0:08:10.240 --> 0:08:14.160 the International Monetary Fund, the Birj Khalifa Tower in Dubai, 0:08:14.360 --> 0:08:17.640 the world's tallest building, required more than a hundred and 0:08:17.640 --> 0:08:20.760 twenty one thousand tons or about a hundred and ten 0:08:20.840 --> 0:08:24.640 thousand metric tons of concrete and over one point six 0:08:24.720 --> 0:08:29.280 million square meters of glass. Another industrial commodity that's a 0:08:29.280 --> 0:08:33.839 massive consumer of sand, Dubai represents another of the great 0:08:33.920 --> 0:08:37.920 tragic ironies of the global sand trade. This booming desert 0:08:37.960 --> 0:08:42.119 outposts surrounded by endless seas of sand dunes, must import 0:08:42.240 --> 0:08:46.240 most of its construction sand from Australia. That's because desert 0:08:46.320 --> 0:08:50.280 sand is too smooth and fine. The rough angular sand 0:08:50.320 --> 0:08:52.960 required to make concrete can only be found in or 0:08:53.000 --> 0:08:57.520 near water or an ancient seabed deposits underground. Of course, 0:08:57.640 --> 0:09:00.800 Dubai isn't alone in its hunger for concrete. According to 0:09:00.800 --> 0:09:04.800 a twenty fourteen UN report on global urbanization, fifty four 0:09:04.840 --> 0:09:07.920 percent of the world's population now lives in urban areas, 0:09:07.960 --> 0:09:12.000 including twenty eight mega cities, Sprawling urban areas with more 0:09:12.040 --> 0:09:16.040 than ten million people. The global sand trade generates seventy 0:09:16.120 --> 0:09:20.079 billion dollars a year to mine, dredge, extract, and ship 0:09:20.200 --> 0:09:24.000 enough raw material to meet the explosive demand for urban housing. 0:09:24.679 --> 0:09:27.800 How long though, until we run out of sand? It 0:09:27.880 --> 0:09:31.000 takes twenty thousand years for the natural process of sand 0:09:31.000 --> 0:09:35.280 formations as dellastrak. Ocean sand begins its journey high in 0:09:35.320 --> 0:09:39.360 the mountains, where erosive forces slowly break rocks into smaller 0:09:39.400 --> 0:09:42.640 and smaller pieces that are eventually carried by streams and 0:09:42.760 --> 0:09:46.720 rivers into the sea. The ocean floor contains a surprisingly 0:09:46.800 --> 0:09:50.800 thin layer of sand. Most large deposits are found on beaches. 0:09:51.640 --> 0:09:54.920 The scarcity of natural sand makes beaches and shorelines the 0:09:55.040 --> 0:09:58.880 ripest targets for both legal and illegal sand mining. The 0:09:59.000 --> 0:10:03.680 environmental impact of large scale sand excavation can be disastrous. 0:10:03.720 --> 0:10:07.160 More than two dozen small islands in Indonesia have disappeared 0:10:07.200 --> 0:10:11.760 due to runaway erosion caused by offshore dredging operations. In 0:10:11.800 --> 0:10:15.520 the United States, a sim x sand mining California's Monterey 0:10:15.520 --> 0:10:20.160 Bay is blamed by environmentalists for rapid coastal erosion. John 0:10:20.200 --> 0:10:24.120 gillis a retired history professor from Rutger's University and author 0:10:24.160 --> 0:10:27.960 of The Human Shore Sea coasts in history, says the 0:10:28.000 --> 0:10:31.240 most immediate human victims of sand mining and sand theft 0:10:31.240 --> 0:10:35.079 are poor fishing communities in the Third World. Quote as 0:10:35.160 --> 0:10:38.600 sand gains value in scarcity and becomes a commodity, you 0:10:38.640 --> 0:10:42.600 see what happens. It disrupts not just the biological systems 0:10:42.600 --> 0:10:46.240 of these places, but also the social systems, driving people 0:10:46.280 --> 0:10:50.040 away from their very tenuous hold on the shore. But 0:10:50.120 --> 0:10:53.000 if sand mining is left unchecked, the damage to coastal 0:10:53.040 --> 0:10:57.400 ecosystems could start swallowing up beaches closer to home. One 0:10:57.440 --> 0:11:02.040 more thing, documentary filmmaker Deleastra says that large scale recycling 0:11:02.080 --> 0:11:06.160 of industrial materials, especially glass and concrete, is one way 0:11:06.200 --> 0:11:10.360 to curb the appetite for natural sand. In Denmark, attacks 0:11:10.400 --> 0:11:14.160 on extracting raw materials has created an incentive for companies 0:11:14.200 --> 0:11:18.520 to recycle. In nineteen five, only twelve percent of construction 0:11:18.520 --> 0:11:21.960 and demolition waste was recycled. By two thousand four, that 0:11:22.040 --> 0:11:33.080 number was finally. This week, staff editor Christopher Hasiotis and 0:11:33.160 --> 0:11:36.360 our freelancer Justcelin Shields have a piece for us about 0:11:36.440 --> 0:11:39.880 one of the fascinating ways that non human animals lacking 0:11:39.880 --> 0:11:47.160 a verbal language communicate with one another. Via poop. Most 0:11:47.200 --> 0:11:49.880 of us agree it's nice to have a special, separate 0:11:49.920 --> 0:11:53.880 area where everyone can relieve themselves. It's objectively great that, 0:11:54.360 --> 0:11:56.880 instead of finding piles of human feces all over the 0:11:56.920 --> 0:11:59.719 airport or grocery store, we extend to one another the 0:11:59.760 --> 0:12:03.120 curb to see if crapping and mutually agreed upon spaces 0:12:03.160 --> 0:12:06.800 so civilized. The very humanness of this act might be 0:12:06.920 --> 0:12:09.680 why when a group of animals all use a shared 0:12:09.720 --> 0:12:14.480 public toilet where all now, isn't that interesting? But let's 0:12:14.480 --> 0:12:18.319 not fool ourselves. Plenty of animal species poop in latrines 0:12:18.679 --> 0:12:21.880 or middens, and it's not just us fancy pants primates, 0:12:22.280 --> 0:12:25.400 nor even just vertebrates. While the act of defecating in 0:12:25.480 --> 0:12:28.840 shared communal dung heaps is common in all manner of mammals, 0:12:28.840 --> 0:12:32.280 from molds to otters to elephants, some species of ants, 0:12:32.280 --> 0:12:36.520 for instance, make refuse chambers in their own nests. Un 0:12:36.559 --> 0:12:39.080 Lest we assume the public toilet is a modern invention, 0:12:39.559 --> 0:12:42.760 The oldest animal latrine ever discovered was created two hundred 0:12:42.840 --> 0:12:47.280 and forty million years ago by a herd of Dinodontosaurus, 0:12:47.440 --> 0:12:50.800 giant herbivorous reptiles that kind of resembled a modern rhino. 0:12:51.840 --> 0:12:55.480 This prehistoric pile of pooh was gargantuan, covering an area 0:12:55.480 --> 0:12:59.480 of almost ten thousand square feet or nine hundred square meters, 0:13:00.000 --> 0:13:02.679 with a poop density of around ninety four tirds per 0:13:02.720 --> 0:13:06.800 square meter. And speaking of the modern rhinoceros, the critically 0:13:06.880 --> 0:13:09.440 endangered white rhino can tell us a lot about what's 0:13:09.480 --> 0:13:12.680 probably going on when animals poop in huge communal piles. 0:13:13.360 --> 0:13:17.560 Why because white rhinos are seriously into smelling each other's crap. 0:13:18.280 --> 0:13:21.679 But let's back up a step. In the past, researchers 0:13:21.720 --> 0:13:23.720 have come up with lots of different reasons why a 0:13:23.760 --> 0:13:26.920 population of animals would want to create a communal midden 0:13:27.520 --> 0:13:30.160 rather than just go behind the nearest tree or wherever. 0:13:30.920 --> 0:13:33.880 Since we humans mostly confine our droppings to a specific 0:13:33.880 --> 0:13:37.640 area for sanitary reasons, some biologists have assumed that other 0:13:37.679 --> 0:13:41.960 animals might be doing the same. And sure, social insects 0:13:41.960 --> 0:13:45.479 like ants and spider mites probably do keep their biological 0:13:45.520 --> 0:13:48.559 waste and uneaten food separate from their communal living spaces 0:13:49.000 --> 0:13:52.120 with the intention of keeping harmful bacteria at bay. But 0:13:52.240 --> 0:13:55.080 many other animals, like the white rhino we're talking about, 0:13:55.400 --> 0:13:58.120 will regularly just stroll up to a giant pile of 0:13:58.120 --> 0:14:02.640 poop and give it a good, thorough investigatory snuffle. They're 0:14:02.640 --> 0:14:06.640 probably not all that worried about germs. So communal latrines 0:14:06.679 --> 0:14:10.080 have also been thought to mark borders of territories or 0:14:10.120 --> 0:14:13.280 even communicate to predators that this heart is large enough 0:14:13.320 --> 0:14:15.120 that lunch isn't going to serve itself to them on 0:14:15.200 --> 0:14:19.480 golden platters. But for some species, scientists think the purpose 0:14:19.480 --> 0:14:24.640 of communal latrines is for intraspecies communication. Period. Take Courtney 0:14:24.680 --> 0:14:28.040 Marnoik for example. She is an ecologist and doctoral student 0:14:28.040 --> 0:14:31.600 at the University of Quasulu Natal in South Africa, and 0:14:31.640 --> 0:14:34.080 she's the lead author of recent study investigating the role 0:14:34.120 --> 0:14:37.840 of dung in white rhino communication. White rhinos use communal 0:14:37.840 --> 0:14:40.680 defecation sites to communicate. She tells, how stuff works and 0:14:40.760 --> 0:14:43.600 this is the only reason they do this. They can 0:14:43.640 --> 0:14:48.560 identify age, sex, territorial state, estra state of the depositor, 0:14:48.800 --> 0:14:51.520 and even how long ago they were there. And although 0:14:51.560 --> 0:14:53.960 Marnoick didn't test for this in her recent study, she 0:14:54.080 --> 0:14:58.720 believes rhinos can recognize specific individuals through fecal scent. One 0:14:58.760 --> 0:15:01.600 interesting thing about white rhine no midden making behavior is 0:15:01.640 --> 0:15:04.360 that every rhino of every age in the area will 0:15:04.440 --> 0:15:07.440 all use the same dung heap, but the only one 0:15:07.440 --> 0:15:09.360 allowed to poop right in the very center of the 0:15:09.360 --> 0:15:13.560 pile is the resident dominant male. He's also the only 0:15:13.600 --> 0:15:16.600 one who kicks his dunge around afterwards, spreading his smell 0:15:16.640 --> 0:15:19.000 around the midden, but also carrying the smell of his 0:15:19.040 --> 0:15:22.760 own poop with him everywhere he walks. According to Marnock, 0:15:23.080 --> 0:15:27.080 lots of other animals, both herbivores and carnivores, used communal 0:15:27.120 --> 0:15:30.760 defecation sites for communication, sometimes only to mark territory and 0:15:30.800 --> 0:15:34.000 pick up signals from other animals, sometimes just for keeping 0:15:34.000 --> 0:15:38.920 track of estrus females, and often both, particularly for herbivores species. 0:15:38.920 --> 0:15:42.280 She says, there's this hypothesis that communal defecation sites could 0:15:42.280 --> 0:15:46.680 potentially be for parasite avoidance, basically, don't crap where you eat. 0:15:47.680 --> 0:15:50.160 She highly doubts that this is the case, though, and 0:15:50.240 --> 0:15:54.520 thanks communication is the reason for all species. So next 0:15:54.560 --> 0:15:56.440 time you're in a public bathroom, you might want to 0:15:56.440 --> 0:15:59.560 look around or take a sniff and see what the 0:15:59.600 --> 0:16:03.640 world's telling you. Oh and one more thing, completely unrelated 0:16:03.640 --> 0:16:07.520 to Rhino's but fascinating. Nonetheless, since we're talking about animal 0:16:07.560 --> 0:16:11.080 bathroom habits here, let's talk about sloths. Though they don't 0:16:11.160 --> 0:16:14.640 use shared latrines, they do only poop about once a week. 0:16:15.240 --> 0:16:17.480 In fact, it's the only reason they climb out of 0:16:17.480 --> 0:16:19.760 the tree. And because it takes up to a month 0:16:19.880 --> 0:16:24.800 for a sloth to digest its food, they're always very constipated. 0:16:25.480 --> 0:16:29.240 That's why each week, defecating sloths undergo what biologists describe 0:16:29.280 --> 0:16:39.320 as an ordeal akin to Chipper. Now, that's our show 0:16:39.320 --> 0:16:41.440 for this week. Thank you so much for tuning in. 0:16:41.760 --> 0:16:44.840 Further thanks for audio producer Dylan Fagin and our orial 0:16:44.920 --> 0:16:48.680 liaison Alison Laddermilk. Subscribe to now Now for more of 0:16:48.680 --> 0:16:50.920 the latest science news, and send this links to anything 0:16:50.920 --> 0:16:53.400 you'd like to hear his cover. Plus tell me what 0:16:53.440 --> 0:16:56.160 you're reading right now. I'm reading Grant Morrison's comic The 0:16:56.160 --> 0:16:59.160 Invisibles for the first time. Uh and it's very not 0:16:59.280 --> 0:17:02.400 safe for work. It very excellent. You can send us 0:17:02.400 --> 0:17:05.560 an email at now Podcast at how stuff works dot com, 0:17:05.600 --> 0:17:08.600 and of course, for lots more stories like these, head 0:17:08.600 --> 0:17:11.440 on over to our home planet now dot how stuff 0:17:11.480 --> 0:17:17.320 works dot com.