1 00:00:07,235 --> 00:00:11,185 Somewhere near you, an animal is defecating. 2 00:00:11,185 --> 00:00:15,576 In fact, each day, the animal kingdom produces roughly enough dung 3 00:00:15,576 --> 00:00:21,566 to match the volume of water pouring over the Victoria Falls. 4 00:00:21,566 --> 00:00:24,934 So why isn’t the planet covered in the stuff? 5 00:00:24,934 --> 00:00:29,244 You can thank the humble dung beetle for eating up the excess. 6 00:00:29,244 --> 00:00:34,568 Capable of burying 250 times their body weight in a single night, 7 00:00:34,568 --> 00:00:40,253 these valiant insects make quick work of an endless stream of feces. 8 00:00:40,253 --> 00:00:46,065 Over 7,000 known species of dung beetle run clean-up duty across six continents 9 00:00:46,065 --> 00:00:48,785 —everywhere except Antarctica. 10 00:00:48,785 --> 00:00:51,924 A dung beetle’s first task is to locate dung. 11 00:00:51,924 --> 00:00:54,954 Some live on the anal regions of larger animals, 12 00:00:54,954 --> 00:00:57,493 ready to leap off when they defecate. 13 00:00:57,493 --> 00:01:01,986 Others sniff out feces that animals leave behind. 14 00:01:01,986 --> 00:01:07,055 A pile of elephant dung can attract 4,000 beetles in 15 minutes. 15 00:01:07,055 --> 00:01:08,868 So once a beetle finds dung, 16 00:01:08,868 --> 00:01:12,964 it must work quickly to secure some of the bounty for itself. 17 00:01:12,964 --> 00:01:16,935 Most dung beetle species fall into one of three main groups: 18 00:01:16,935 --> 00:01:17,878 rollers, 19 00:01:17,878 --> 00:01:18,749 tunellers, 20 00:01:18,749 --> 00:01:21,254 and dwellers. 21 00:01:21,254 --> 00:01:25,253 Dung rollers sculpt a ball of dung, and using their back legs, 22 00:01:25,253 --> 00:01:28,447 quickly roll it away from competitors. 23 00:01:28,447 --> 00:01:30,434 Potential partners jump on the ball, 24 00:01:30,434 --> 00:01:32,975 and once the ball-maker has selected their mate, 25 00:01:32,975 --> 00:01:36,375 the pair dig their dung ball into the soil. 26 00:01:36,375 --> 00:01:41,614 Once it’s been buried, the female lays a single egg within the dung ball. 27 00:01:41,614 --> 00:01:43,654 Tunnelers have a different approach. 28 00:01:43,654 --> 00:01:47,536 Digging underneath a pat, some drag dung down into the soil 29 00:01:47,536 --> 00:01:50,896 and pack it into clumps known as brood balls, 30 00:01:50,896 --> 00:01:52,004 dung balls, 31 00:01:52,004 --> 00:01:56,305 or dung “sausages,” depending on their shape and size. 32 00:01:56,305 --> 00:02:00,205 Male tunnelers sport a spectacular array of horns 33 00:02:00,205 --> 00:02:02,595 to fight each other for control of these tunnels, 34 00:02:02,595 --> 00:02:06,770 which they then defend until the female’s laid her egg. 35 00:02:06,770 --> 00:02:12,027 Some male tunnelers avoid the fray by masquerading as hornless females 36 00:02:12,027 --> 00:02:16,795 and sneaking into tunnels to mate while the guardians’ heads are turned. 37 00:02:16,795 --> 00:02:19,355 The third group of dung beetles, dwellers, 38 00:02:19,355 --> 00:02:21,634 take the most straightforward approach, 39 00:02:21,634 --> 00:02:25,135 laying their eggs directly into a dung pat. 40 00:02:25,135 --> 00:02:28,016 This makes their offspring more vulnerable to predation 41 00:02:28,016 --> 00:02:30,645 than those of the tunnelers and rollers. 42 00:02:30,645 --> 00:02:34,084 As the larvae feed, they riddle the dung pat with tunnels, 43 00:02:34,084 --> 00:02:39,754 leaving remains that are quickly colonized by bacteria and fungi and weathered away. 44 00:02:39,754 --> 00:02:43,896 Inside a tunnel, ball, or pat, once the larvae hatch, 45 00:02:43,896 --> 00:02:47,514 they consume the dung before metamorphosing into a pupa 46 00:02:47,514 --> 00:02:50,295 and then an adult beetle. 47 00:02:50,295 --> 00:02:53,375 Besides clearing dung, the actions of these beetles 48 00:02:53,375 --> 00:02:56,666 have considerable ecological importance. 49 00:02:56,666 --> 00:03:00,625 For one, they serve as secondary seed dispersers. 50 00:03:00,625 --> 00:03:02,035 Dung from monkeys, 51 00:03:02,035 --> 00:03:02,894 wild pigs, 52 00:03:02,894 --> 00:03:06,744 and other animals is riddled with seeds from the fruits they eat. 53 00:03:06,744 --> 00:03:08,875 When beetles bury their dung balls, 54 00:03:08,875 --> 00:03:12,004 they inadvertently protect these seeds from predators 55 00:03:12,004 --> 00:03:15,086 and increase the likelihood they’ll germinate. 56 00:03:15,086 --> 00:03:18,494 The advantage is so great that one South African plant 57 00:03:18,494 --> 00:03:22,844 has evolved to produce seeds that look and smell like dung 58 00:03:22,844 --> 00:03:25,873 to trick beetles into burying them. 59 00:03:25,873 --> 00:03:30,156 Dung beetles also play important roles in agricultural systems. 60 00:03:30,156 --> 00:03:34,004 Livestock, like cows and sheep, produce huge amounts of dung, 61 00:03:34,004 --> 00:03:37,645 which contains nutrients that can benefit plants. 62 00:03:37,645 --> 00:03:41,525 The beetles break up the dung and tunnel it deep into the soil, 63 00:03:41,525 --> 00:03:45,825 bringing the nutrients into close contact with plant roots. 64 00:03:45,825 --> 00:03:51,767 Their services to farmers have been valued at $380 million a year in the US 65 00:03:51,767 --> 00:03:56,094 and £367 million a year in the UK. 66 00:03:56,094 --> 00:03:59,196 Dung beetles can even help us battle global warming 67 00:03:59,196 --> 00:04:03,476 by reducing greenhouse gas emissions associated with farming. 68 00:04:03,476 --> 00:04:06,796 Microbes living in oxygen-poor livestock dung 69 00:04:06,796 --> 00:04:10,685 produce methane, a potent greenhouse gas. 70 00:04:10,685 --> 00:04:14,175 But beetles oxygenate pats when they tunnel into them, 71 00:04:14,175 --> 00:04:17,624 preventing the microbes from producing methane. 72 00:04:17,624 --> 00:04:19,525 The dung beetle spreads seeds, 73 00:04:19,525 --> 00:04:20,594 helps farmers, 74 00:04:20,594 --> 00:04:22,435 and fights climate change 75 00:04:22,435 --> 00:04:26,675 —and accomplishes it all simply by doing its business. 76 00:04:26,675 --> 00:04:30,465 Maybe next time you come across some dung in the forest or a field, 77 00:04:30,465 --> 00:04:32,945 you’ll be tempted to take a closer look.