1 00:00:01,051 --> 00:00:03,968 (mysterious music) 2 00:00:19,528 --> 00:00:22,028 A teeming ant colony. 3 00:00:22,970 --> 00:00:26,030 A society where worker ants labor blindly 4 00:00:26,030 --> 00:00:27,380 for the good of the colony, 5 00:00:28,410 --> 00:00:30,713 just cogs in a living machine. 6 00:00:34,430 --> 00:00:37,483 A huge collective with a single-minded purpose. 7 00:00:40,340 --> 00:00:43,320 The ultimate stuff of sci-fi movies. 8 00:00:43,320 --> 00:00:47,070 (mysterious music continues) 9 00:00:54,140 --> 00:00:58,263 Scary, ruthless, relentless. 10 00:01:00,240 --> 00:01:01,193 Truly alien. 11 00:01:06,840 --> 00:01:08,103 But look closer, 12 00:01:12,810 --> 00:01:17,290 an ant colony has the run of the whole of this house, 13 00:01:17,290 --> 00:01:18,470 giving a unique look 14 00:01:18,470 --> 00:01:21,483 at the lives of these intriguing little insects. 15 00:01:27,190 --> 00:01:31,330 These colonies are far more sophisticated than we imagine. 16 00:01:31,330 --> 00:01:34,400 Not a dystopian nightmare at all, 17 00:01:34,400 --> 00:01:35,933 but a caring society. 18 00:01:37,517 --> 00:01:40,090 (dramatic music) 19 00:01:40,090 --> 00:01:44,820 In the nurseries, workers tend huge piles of eggs, 20 00:01:44,820 --> 00:01:47,383 keeping them clean and free from infection. 21 00:01:50,260 --> 00:01:51,853 Others wait on the queen. 22 00:01:53,020 --> 00:01:54,693 The only one to breed. 23 00:01:55,870 --> 00:01:58,460 Collecting her eggs as soon as they're laid 24 00:01:58,460 --> 00:02:00,593 and taking them straight to the nursery. 25 00:02:03,060 --> 00:02:05,450 Some workers care for the pupae, 26 00:02:05,450 --> 00:02:09,373 about to emerge as fresh recruits to the vast workforce. 27 00:02:16,300 --> 00:02:20,210 This is why social insects are so distinctive. 28 00:02:20,210 --> 00:02:23,490 All these individual insects cooperate closely 29 00:02:24,420 --> 00:02:26,483 for the good of their whole society. 30 00:02:31,100 --> 00:02:33,443 It's one for all and all for one. 31 00:02:34,670 --> 00:02:37,550 Without a selfish thought in any kind of head. 32 00:02:39,118 --> 00:02:42,701 (dramatic music continues) 33 00:02:51,160 --> 00:02:54,450 Working together in large colonies like this, 34 00:02:54,450 --> 00:02:58,390 makes social insects the most successful of all insects. 35 00:03:00,540 --> 00:03:02,700 Yet only two different groups of insects 36 00:03:02,700 --> 00:03:06,083 have ever evolved such complex societies. 37 00:03:09,150 --> 00:03:13,260 We're most familiar with the ants, bees and wasps 38 00:03:13,260 --> 00:03:16,293 and they all belong to one insect group. 39 00:03:19,100 --> 00:03:22,453 Societies operating with military precision. 40 00:03:24,310 --> 00:03:26,203 They dominate their world. 41 00:03:30,260 --> 00:03:32,890 In some rainforests ants outweigh 42 00:03:32,890 --> 00:03:35,683 all the land vertebrates by four times. 43 00:03:40,160 --> 00:03:42,743 And not just in remote wild places. 44 00:03:44,490 --> 00:03:48,313 Teamwork means these insects conquer our world as well. 45 00:03:54,120 --> 00:03:57,023 But these ant colonies don't reign unchallenged. 46 00:04:01,060 --> 00:04:02,113 Termites. 47 00:04:09,150 --> 00:04:12,370 They also live in vast societies just as successful 48 00:04:12,370 --> 00:04:15,853 as those of the ants, bees and wasps. 49 00:04:17,470 --> 00:04:21,693 Working together, some termites build gigantic castles. 50 00:04:25,340 --> 00:04:27,120 They shape the whole landscape 51 00:04:27,120 --> 00:04:28,973 as much as any of the bigger animals. 52 00:04:34,230 --> 00:04:37,220 The total weight of all the termites in the world 53 00:04:37,220 --> 00:04:40,293 is about the same as that of all humans. 54 00:04:44,060 --> 00:04:47,390 How did evolution produce these bustling societies 55 00:04:47,390 --> 00:04:49,603 of insect overachievers? 56 00:04:56,860 --> 00:04:59,780 It's not just in huge colonies. 57 00:04:59,780 --> 00:05:02,950 It turns out the cooperation of one sort or another 58 00:05:02,950 --> 00:05:05,323 is surprisingly common among insects. 59 00:05:14,050 --> 00:05:17,574 In the Australian Bush, there are close knit families 60 00:05:17,574 --> 00:05:20,443 that show the beginnings of cooperation. 61 00:05:21,733 --> 00:05:24,566 (kangaroo grunts) 62 00:05:26,270 --> 00:05:29,313 Some insects really hate to be on their own. 63 00:05:31,270 --> 00:05:34,420 Spitfire bugs are the larva of sawflies 64 00:05:35,490 --> 00:05:38,699 and they stick to each other like glue. 65 00:05:38,699 --> 00:05:41,616 (mysterious music) 66 00:05:46,920 --> 00:05:48,550 When they move, 67 00:05:48,550 --> 00:05:51,393 they keep their tails wrapped around each other. 68 00:06:05,100 --> 00:06:09,320 If one does get separated, the rest drum on the plant, 69 00:06:09,320 --> 00:06:12,493 a powerful homing signal to guide the straggler home. 70 00:06:13,949 --> 00:06:17,282 (caterpillars drumming) 71 00:06:27,393 --> 00:06:30,140 They feed on the leaves of eucalyptus trees 72 00:06:30,140 --> 00:06:32,473 which are packed with pungent oils. 73 00:06:34,280 --> 00:06:36,933 Although that doesn't seem to worry the Spitfires. 74 00:06:40,050 --> 00:06:43,200 But if they feel threatened, they all rear up 75 00:06:43,200 --> 00:06:45,233 and spit drops of fluid, 76 00:06:46,090 --> 00:06:50,623 concentrated eucalyptus oil, nasty stuff. 77 00:06:57,210 --> 00:06:58,740 They even thrash their tails 78 00:06:58,740 --> 00:07:01,410 to coat their bodies in the oil. 79 00:07:01,410 --> 00:07:03,180 So anything that comes too close 80 00:07:03,180 --> 00:07:05,563 will get coated with stinking fluid. 81 00:07:15,050 --> 00:07:18,250 This show of solidarity is enough for most predators 82 00:07:18,250 --> 00:07:20,520 to leave them well alone. 83 00:07:20,520 --> 00:07:24,373 They're much safer in a group, a basic society. 84 00:07:31,780 --> 00:07:34,790 But a society where members of the same generation 85 00:07:34,790 --> 00:07:37,450 work together doesn't go much further 86 00:07:37,450 --> 00:07:39,533 than these bands of feisty caterpillars. 87 00:07:53,510 --> 00:07:55,660 It takes a different kind of community 88 00:07:55,660 --> 00:07:58,733 for evolution to really work its magic. 89 00:08:02,070 --> 00:08:04,730 A bond built across the generations 90 00:08:04,730 --> 00:08:06,783 between parents and offspring. 91 00:08:10,240 --> 00:08:13,681 Meet the world's biggest roach. 92 00:08:13,681 --> 00:08:17,150 (roach scuttling) 93 00:08:17,150 --> 00:08:19,720 These four inch rhinoceros roaches 94 00:08:19,720 --> 00:08:23,020 only live in these Australian forests 95 00:08:23,020 --> 00:08:26,202 where they feed on dried gum leaves. 96 00:08:26,202 --> 00:08:29,119 (mysterious music) 97 00:08:38,070 --> 00:08:40,663 The bulldozers of the insect world. 98 00:08:41,840 --> 00:08:44,760 They have powerful front legs to dig burrows 99 00:08:44,760 --> 00:08:46,403 in the hard-packed earth. 100 00:08:55,500 --> 00:08:57,373 Very deep burrows. 101 00:09:00,302 --> 00:09:04,052 (mysterious music continues) 102 00:09:06,070 --> 00:09:07,830 Following a winding path 103 00:09:07,830 --> 00:09:11,040 it descends below the forest floor, 104 00:09:11,040 --> 00:09:12,463 deeper and deeper. 105 00:09:19,410 --> 00:09:23,680 Eventually, more than three feet below the surface 106 00:09:23,680 --> 00:09:26,853 is her nest chamber and her family. 107 00:09:35,060 --> 00:09:38,763 The baby roaches are happy to see her, it's dinner time. 108 00:09:39,960 --> 00:09:43,610 She drags these unappetizing dried leaves all the way 109 00:09:43,610 --> 00:09:46,150 down to the nest and the young feed 110 00:09:46,150 --> 00:09:48,473 on the fragments that she chews off for them. 111 00:09:59,070 --> 00:10:02,150 But this diet is really hard to digest, 112 00:10:02,150 --> 00:10:03,593 at least without help. 113 00:10:04,880 --> 00:10:08,340 Just like cows, these roaches need guts 114 00:10:08,340 --> 00:10:11,363 packed with microbes to break down the leaves. 115 00:10:16,650 --> 00:10:20,430 The problem is the young don't have their own microbes. 116 00:10:20,430 --> 00:10:22,463 They need to get them from their mother. 117 00:10:25,800 --> 00:10:29,263 The only way to do that is to eat moms poo. 118 00:10:31,380 --> 00:10:35,300 This tough cellulose diet means that young cockroaches 119 00:10:35,300 --> 00:10:37,020 must hang around their parents 120 00:10:37,020 --> 00:10:39,453 until they have their own gut flora. 121 00:10:46,630 --> 00:10:48,080 They'll stay with their mother 122 00:10:48,080 --> 00:10:50,023 for the whole of the summer. 123 00:10:56,460 --> 00:10:59,690 But if the kids never leave home 124 00:10:59,690 --> 00:11:03,323 the family just gets bigger and bigger. 125 00:11:05,460 --> 00:11:08,822 Which is exactly how termites evolved. 126 00:11:08,822 --> 00:11:12,070 (mysterious music) 127 00:11:12,070 --> 00:11:15,050 Termites are just social roaches. 128 00:11:15,050 --> 00:11:17,633 Very, very social roaches. 129 00:11:24,080 --> 00:11:26,920 These are Darwin's termites, 130 00:11:26,920 --> 00:11:30,873 the most primitive and the largest of all termites. 131 00:11:36,100 --> 00:11:39,790 This is all one family of brothers and sisters. 132 00:11:39,790 --> 00:11:43,380 They'll never leave home and never breed themselves. 133 00:11:43,380 --> 00:11:45,310 They'll spend the rest of their lives 134 00:11:45,310 --> 00:11:47,643 helping their mother, the queen. 135 00:11:53,150 --> 00:11:55,770 Some are specialized soldiers 136 00:11:55,770 --> 00:11:58,743 with powerful jaws to defend their colony. 137 00:12:04,040 --> 00:12:06,563 But the rest just chew on wood. 138 00:12:08,180 --> 00:12:10,593 Hollowing out entire trees. 139 00:12:15,270 --> 00:12:16,730 Darwin's termites are one 140 00:12:16,730 --> 00:12:19,393 of the most destructive termites in the world. 141 00:12:23,200 --> 00:12:26,150 Termites don't care whether wood is growing as a tree 142 00:12:26,150 --> 00:12:29,723 in a forest, or has been turned into a home. 143 00:12:33,150 --> 00:12:35,153 It's all just food to them. 144 00:12:40,110 --> 00:12:42,250 Dry wood termites like these, 145 00:12:42,250 --> 00:12:45,030 are much smaller than Darwin's termites, 146 00:12:45,030 --> 00:12:48,060 but still cause millions of dollars worth of damage 147 00:12:48,060 --> 00:12:50,053 in the world's warmer regions. 148 00:12:54,220 --> 00:12:56,400 Like their roach ancestors, 149 00:12:56,400 --> 00:12:59,290 they also have guts packed with microbes, 150 00:12:59,290 --> 00:13:02,363 so termites can digest anything made of wood. 151 00:13:09,550 --> 00:13:11,240 The chewed off fragments of wood 152 00:13:11,240 --> 00:13:14,153 are pulverized further by a muscular gizzard. 153 00:13:20,060 --> 00:13:22,900 Then pass along the gut where the termite's 154 00:13:22,900 --> 00:13:25,343 own enzymes begin digestion. 155 00:13:27,040 --> 00:13:28,730 Then the fragments are handed over 156 00:13:28,730 --> 00:13:31,320 to protozoans and bacteria. 157 00:13:31,320 --> 00:13:34,933 So many, they make up nearly half the termites weight. 158 00:13:40,540 --> 00:13:44,000 This tough diet of wood and dried plants 159 00:13:44,000 --> 00:13:46,780 forces the young to stay at home for a long time 160 00:13:47,910 --> 00:13:51,953 to inherit these vital microorganisms from their parents. 161 00:13:56,080 --> 00:13:59,610 A long lasting bond between parents and young 162 00:13:59,610 --> 00:14:02,100 gave termites the opportunity to evolve 163 00:14:02,100 --> 00:14:04,213 their complex societies. 164 00:14:08,160 --> 00:14:10,980 A few billion bacteria and protozoans 165 00:14:10,980 --> 00:14:14,040 keep these vast colonies sustained 166 00:14:14,040 --> 00:14:16,380 by nothing more than dry wood. 167 00:14:20,150 --> 00:14:22,610 Although we don't usually appreciate just what 168 00:14:22,610 --> 00:14:26,083 extraordinary little creatures termites really are. 169 00:14:30,041 --> 00:14:32,182 (wood creaking) 170 00:14:32,182 --> 00:14:35,015 (wood fracturing) 171 00:14:49,032 --> 00:14:52,115 (objects clattering) 172 00:14:53,284 --> 00:14:56,534 On the other hand, everyone loves bees. 173 00:15:00,020 --> 00:15:04,120 Bee societies are just as complex as those of termites 174 00:15:04,120 --> 00:15:07,282 but came about in a very different way. 175 00:15:07,282 --> 00:15:10,040 (gentle music) 176 00:15:10,040 --> 00:15:15,040 The Sonoran Desert in the American Southwest is bee heaven. 177 00:15:16,610 --> 00:15:19,663 A thousand different kinds of bees live here. 178 00:15:24,201 --> 00:15:27,210 (bees buzzing) 179 00:15:27,210 --> 00:15:31,010 We think of bees as living in huge super colonies, 180 00:15:31,010 --> 00:15:34,843 but most kinds of bees are actually very antisocial. 181 00:15:38,130 --> 00:15:41,003 And that includes cactus bees. 182 00:15:44,420 --> 00:15:48,233 There may be thousands of bees in this one patch of desert, 183 00:15:49,430 --> 00:15:52,183 but it's every bee for herself. 184 00:15:54,050 --> 00:15:57,323 She's only focused on digging her own nest. 185 00:15:59,820 --> 00:16:02,120 (gentle music continues) 186 00:16:02,120 --> 00:16:05,423 A tunnel in the hard, dry, desert soil. 187 00:16:10,050 --> 00:16:13,070 They're all crammed into this one neighborhood 188 00:16:13,070 --> 00:16:16,543 because the soil here is easier to work than elsewhere. 189 00:16:23,120 --> 00:16:24,313 But not that easy. 190 00:16:27,080 --> 00:16:29,833 It's hard work moving boulders bigger than you are. 191 00:16:36,030 --> 00:16:39,943 And once that's done, the nest must be stopped with pollen. 192 00:16:43,170 --> 00:16:46,860 Cactus bees specialize in cactus flowers. 193 00:16:46,860 --> 00:16:49,980 She dives headlong into a sea of anthers. 194 00:16:50,900 --> 00:16:52,133 Laden with pollen. 195 00:17:08,090 --> 00:17:11,013 When she emerges, she's covered in the stuff. 196 00:17:14,390 --> 00:17:17,740 She packs it all onto her hairy hind legs 197 00:17:17,740 --> 00:17:19,533 to carry it back to her nest. 198 00:17:34,750 --> 00:17:38,000 Each nest must be filled with enough pollen and nectar 199 00:17:38,000 --> 00:17:41,013 to feed all her larvae until they're fully grown. 200 00:17:45,782 --> 00:17:47,782 But she's being watched. 201 00:17:49,090 --> 00:17:54,090 A bee fly, with a simple mission in life. 202 00:17:56,180 --> 00:17:57,980 Avoid all this effort 203 00:17:57,980 --> 00:18:01,008 and instead exploit the hardworking bees. 204 00:18:01,008 --> 00:18:03,758 (dramatic music) 205 00:18:06,050 --> 00:18:08,323 The fly is a precision bomber. 206 00:18:09,800 --> 00:18:12,553 She flicks her egg towards the bees nest. 207 00:18:14,720 --> 00:18:15,923 And it's a hole in one. 208 00:18:21,140 --> 00:18:25,440 When the fly's grub hatches, it'll eat the pollen store 209 00:18:25,440 --> 00:18:28,453 and kill and eat the bee's own larva. 210 00:18:33,060 --> 00:18:35,860 And this strange creature also has designs 211 00:18:35,860 --> 00:18:37,183 on the bee's larva. 212 00:18:38,600 --> 00:18:42,743 It's a thistledown velvet ant, another parasite. 213 00:18:44,340 --> 00:18:47,490 When the bee leaves to collect yet more pollen, 214 00:18:47,490 --> 00:18:51,733 the velvet ant slips in to lay her own egg deep in the nest. 215 00:18:55,180 --> 00:18:59,000 Parasites like these are a real problem for the bees, 216 00:18:59,000 --> 00:19:02,490 but because they're only concerned with their own nests 217 00:19:02,490 --> 00:19:04,240 they don't look out for each other. 218 00:19:06,358 --> 00:19:08,941 (bees buzzing) 219 00:19:10,040 --> 00:19:12,970 Even with thousands of them packed together, 220 00:19:12,970 --> 00:19:15,023 there's no neighborhood watch. 221 00:19:18,010 --> 00:19:22,693 Bumblebees have solved that problem by becoming social. 222 00:19:28,080 --> 00:19:31,263 A bumblebee nest is never left undefended. 223 00:19:32,100 --> 00:19:34,233 It's always humming with activity. 224 00:19:40,060 --> 00:19:43,833 Like termites, this is just one extended family. 225 00:19:47,060 --> 00:19:49,530 But bee workers are all female. 226 00:19:49,530 --> 00:19:51,293 All daughters of the queen. 227 00:19:56,170 --> 00:20:00,173 She lays her eggs into specially prepared wax pots. 228 00:20:08,150 --> 00:20:11,283 Right away, the workers move in to take care of them. 229 00:20:16,040 --> 00:20:18,910 This army of workers all cooperate to build 230 00:20:18,910 --> 00:20:20,603 and defend their nest. 231 00:20:27,120 --> 00:20:29,163 And they also nurse the growing larvae, 232 00:20:30,800 --> 00:20:32,283 their younger sisters. 233 00:20:37,060 --> 00:20:41,350 By working together, insect societies can prosper and grow. 234 00:20:46,244 --> 00:20:48,480 Though most of these colonies must begin life 235 00:20:48,480 --> 00:20:50,273 with just a single parent. 236 00:20:52,247 --> 00:20:53,447 The time of most danger. 237 00:20:54,347 --> 00:20:57,180 (thunder rumbles) 238 00:21:02,090 --> 00:21:06,223 A green tree ant, a queen, all alone. 239 00:21:11,020 --> 00:21:15,310 For most kinds of ants, a young queen starting a new colony 240 00:21:15,310 --> 00:21:18,003 hides in a crevice or a hole in the ground. 241 00:21:19,618 --> 00:21:22,723 But a green tree ant lives in trees. 242 00:21:26,020 --> 00:21:29,900 With fewer places to hide, she has no choice 243 00:21:29,900 --> 00:21:32,690 but to stand over her first batch of eggs 244 00:21:33,650 --> 00:21:36,371 and try to look intimidating. 245 00:21:36,371 --> 00:21:39,700 (tense music) 246 00:21:39,700 --> 00:21:42,360 With no help from workers or guards, 247 00:21:42,360 --> 00:21:45,429 only a tiny fraction of new queens survive 248 00:21:45,429 --> 00:21:47,753 to found a new dynasty. 249 00:21:50,070 --> 00:21:54,120 But one day, if she's lucky, she'll be head of an army 250 00:21:54,120 --> 00:21:55,653 of maybe half a million. 251 00:21:56,990 --> 00:22:01,454 Now, working as one, they're the scourge of the treetops. 252 00:22:01,454 --> 00:22:04,121 (ominous music) 253 00:22:11,840 --> 00:22:13,493 Nothing is safe up here. 254 00:22:19,090 --> 00:22:23,173 Even big insects are overwhelmed by sheer force of numbers. 255 00:22:32,339 --> 00:22:36,613 These ants really show what's possible with teamwork. 256 00:22:38,922 --> 00:22:41,070 If they come to a gap too wide to cross, 257 00:22:41,070 --> 00:22:43,293 they work together to bridge it. 258 00:22:50,050 --> 00:22:53,670 A few ants brace themselves as anchors. 259 00:22:53,670 --> 00:22:55,700 Then other ants climb over their bodies 260 00:22:55,700 --> 00:22:58,060 and take a firm hold. 261 00:22:58,060 --> 00:22:59,690 Yet more ants pile on 262 00:22:59,690 --> 00:23:01,693 until they have built the living bridge. 263 00:23:14,070 --> 00:23:16,683 Now the army can stream across, 264 00:23:21,350 --> 00:23:23,573 to lay waste to a new branch. 265 00:23:32,090 --> 00:23:35,543 Legions of ants carry the prey back to the nest. 266 00:23:49,535 --> 00:23:53,400 And their nests themselves, made of folded leaves, 267 00:23:53,400 --> 00:23:56,815 couldn't be built without even closer cooperation. 268 00:23:56,815 --> 00:23:59,815 (suspenseful music) 269 00:24:02,190 --> 00:24:04,440 Each ant grabs the edge of leaf. 270 00:24:12,140 --> 00:24:14,210 On its own, a single ant 271 00:24:14,210 --> 00:24:16,123 isn't strong enough to bend the leaf, 272 00:24:16,970 --> 00:24:21,300 but like a well trained crew of sailors hoisting a sail, 273 00:24:21,300 --> 00:24:24,193 they all heave together to fold the leaf over. 274 00:24:40,740 --> 00:24:42,020 Now all they need is a way 275 00:24:42,020 --> 00:24:44,483 to fix the leaves in place permanently. 276 00:24:49,150 --> 00:24:52,000 More ants arrive at the construction site, 277 00:24:52,000 --> 00:24:54,207 carrying fully grown larvae. 278 00:24:59,335 --> 00:25:01,918 And these larvae can spin silk. 279 00:25:09,040 --> 00:25:12,230 The workers use them like glue guns, 280 00:25:12,230 --> 00:25:14,423 moving them between the leaf edges. 281 00:25:15,660 --> 00:25:19,400 Slowly building up more and more strands of silk 282 00:25:19,400 --> 00:25:22,323 until they're thick enough to stitch the leaves together. 283 00:25:39,070 --> 00:25:43,123 Before long, they've built a secure treetop home. 284 00:25:49,050 --> 00:25:52,393 Most other ants build their homes below ground. 285 00:25:53,230 --> 00:25:55,510 Even though they're more elaborate, 286 00:25:55,510 --> 00:25:58,543 all that shows on the surface is a tiny hole. 287 00:26:03,590 --> 00:26:05,770 But beneath the surface... 288 00:26:08,010 --> 00:26:10,593 (gentle music) 289 00:26:12,040 --> 00:26:15,110 These are aluminum casts of underground networks 290 00:26:15,110 --> 00:26:18,673 of tunnels and chambers made by different kinds of ants. 291 00:26:34,040 --> 00:26:37,190 The casts have been made by pouring molten aluminum 292 00:26:37,190 --> 00:26:40,640 into the entrance hole of an abandoned nest. 293 00:26:40,640 --> 00:26:43,550 Then digging out the solidified metal sculpture 294 00:26:44,670 --> 00:26:47,763 to reveal ant art. 295 00:26:49,086 --> 00:26:52,503 (gentle music continues) 296 00:26:57,040 --> 00:27:00,440 This is another advantage of social living. 297 00:27:00,440 --> 00:27:02,673 Working together, these insects can build 298 00:27:02,673 --> 00:27:04,990 elaborate, secure homes 299 00:27:04,990 --> 00:27:07,993 where they live and rear their extended families. 300 00:27:12,070 --> 00:27:14,390 And from the safety of this base 301 00:27:14,390 --> 00:27:16,613 they can set out to conquer the world. 302 00:27:17,930 --> 00:27:20,313 Theirs and ours. 303 00:27:22,046 --> 00:27:24,963 (traffic rumbling) 304 00:27:32,786 --> 00:27:34,440 Ants are perfectly at home 305 00:27:34,440 --> 00:27:38,060 in the heart of our biggest and busiest cities. 306 00:27:38,060 --> 00:27:42,083 In fact, there are far more ants here than people. 307 00:27:48,090 --> 00:27:51,260 13 different kinds of ants thrive on the streets 308 00:27:51,260 --> 00:27:56,260 of downtown New York, where like us, they crave junk food. 309 00:28:03,070 --> 00:28:05,650 Chemical analysis of these ants has shown 310 00:28:05,650 --> 00:28:08,433 they're eating the same food as the people here. 311 00:28:12,070 --> 00:28:16,793 Like us, they are hooked on burgers, hot dogs and bagels. 312 00:28:19,630 --> 00:28:21,973 The most abundant are pavement ants. 313 00:28:22,900 --> 00:28:25,803 They're tiny, just a fraction of an inch long. 314 00:28:26,870 --> 00:28:29,080 But so efficient, they do a great job 315 00:28:29,080 --> 00:28:32,683 in keeping the sidewalks clear of all the food we waste. 316 00:28:37,480 --> 00:28:41,190 Along just Broadway and West Street, these ants dispose 317 00:28:41,190 --> 00:28:45,020 of over half a million discarded potato chips every year. 318 00:28:51,638 --> 00:28:55,160 These super societies can exploit any resource 319 00:28:55,160 --> 00:28:58,400 so efficiently because they're always 320 00:28:58,400 --> 00:29:00,163 in contact with each other. 321 00:29:06,040 --> 00:29:07,700 This means they can profit quickly 322 00:29:07,700 --> 00:29:11,083 from any opportunity wherever they find it. 323 00:29:17,070 --> 00:29:20,263 Scouts are always searching for a convenient meal. 324 00:29:22,040 --> 00:29:25,660 When these first ants find an all you can eat buffet, 325 00:29:25,660 --> 00:29:27,440 they sample what's on offer. 326 00:29:27,440 --> 00:29:29,833 Then return to the nest with the good news. 327 00:29:35,060 --> 00:29:38,603 On their way back, they lay down chemical trails. 328 00:29:43,070 --> 00:29:45,590 And now hundreds of workers can simply follow 329 00:29:45,590 --> 00:29:48,233 these sign posted ant highways to the feast. 330 00:30:08,568 --> 00:30:11,568 In no time, it's swarming with ants. 331 00:30:12,410 --> 00:30:14,790 Each playing its part in the supply chain 332 00:30:14,790 --> 00:30:16,093 back to the nest. 333 00:30:22,630 --> 00:30:25,280 These efficient bands of foragers are crucial 334 00:30:25,280 --> 00:30:28,733 to the survival of all these insect societies. 335 00:30:29,670 --> 00:30:32,143 So every new recruit counts. 336 00:30:33,484 --> 00:30:37,143 Another worker is about to join team bumblebee. 337 00:30:39,840 --> 00:30:41,943 With a little help from her sisters. 338 00:31:08,180 --> 00:31:10,220 She's a bit disheveled at first 339 00:31:10,220 --> 00:31:13,443 but it doesn't take her long to dry off and fluff up. 340 00:31:22,080 --> 00:31:24,010 And then she's ready to play her part 341 00:31:24,010 --> 00:31:26,203 in keeping the colony well stocked. 342 00:31:27,571 --> 00:31:30,071 (bee buzzing) 343 00:31:33,170 --> 00:31:35,900 It's an awfully big world out there 344 00:31:35,900 --> 00:31:37,790 and to be an effective team member 345 00:31:37,790 --> 00:31:41,003 she has a lot to learn in a short space of time. 346 00:31:43,030 --> 00:31:45,393 She'll probably only live for a month or so. 347 00:31:51,140 --> 00:31:55,020 Bumblebee societies are fueled by pollen and nectar, 348 00:31:55,020 --> 00:31:58,660 but there's a vast choice of flowers in this meadow. 349 00:31:58,660 --> 00:32:02,741 How on earth can she ever learn which ones are the best? 350 00:32:02,741 --> 00:32:05,324 (gentle music) 351 00:32:11,142 --> 00:32:15,280 A young worker learns from other more experienced bees. 352 00:32:15,280 --> 00:32:17,343 Even bees of different species. 353 00:32:21,020 --> 00:32:23,973 If a honey bee thinks this kind of flower is good, 354 00:32:25,140 --> 00:32:26,687 maybe worth checking it out. 355 00:32:39,020 --> 00:32:41,400 The young bumblebee samples any flowers 356 00:32:41,400 --> 00:32:43,623 that she sees other bees feeding on. 357 00:32:45,150 --> 00:32:47,737 So it doesn't take her long to learn for herself 358 00:32:47,737 --> 00:32:50,733 which are the best sources of nectar and pollen. 359 00:33:14,150 --> 00:33:16,553 She soon becomes an efficient forager. 360 00:33:21,090 --> 00:33:25,750 By now the pollen sacks on her back legs are bulging, 361 00:33:25,750 --> 00:33:28,443 time to get these supplies back to the nest. 362 00:33:36,090 --> 00:33:39,163 She scrapes the pollen into one of the storage pots, 363 00:33:40,070 --> 00:33:41,943 and she's ready for her next mission. 364 00:33:56,300 --> 00:33:58,430 Bumblebee colonies are small, 365 00:33:58,430 --> 00:34:01,310 rarely more than a few hundred workers, 366 00:34:01,310 --> 00:34:03,793 the bee equivalent of a small village. 367 00:34:07,770 --> 00:34:09,900 But in some places, 368 00:34:09,900 --> 00:34:12,243 bees build up much larger cities. 369 00:34:17,100 --> 00:34:20,460 In the tropics, there's a year round supply of food 370 00:34:20,460 --> 00:34:25,460 which feeds a thriving metropolis of stingless bees. 371 00:34:25,686 --> 00:34:29,050 (bees humming) 372 00:34:29,050 --> 00:34:31,030 They nest in hollow trees 373 00:34:31,030 --> 00:34:32,950 and build a narrow entrance tunnel 374 00:34:32,950 --> 00:34:35,393 which is constantly manned by guards. 375 00:34:43,010 --> 00:34:46,023 Only members of the colony are allowed to pass. 376 00:34:49,020 --> 00:34:52,523 The tunnel leads to a sophisticated, intricate nest. 377 00:35:02,060 --> 00:35:04,773 It has graceful spirals of brood cells. 378 00:35:10,153 --> 00:35:14,736 And the whole structure is braced by arches and struts. 379 00:35:23,634 --> 00:35:25,750 But the most complex structures 380 00:35:25,750 --> 00:35:28,063 are not made by bees or ants. 381 00:35:31,843 --> 00:35:35,093 (go-away bird calling) 382 00:35:36,330 --> 00:35:38,823 Not all termites tunnel through wood, 383 00:35:40,830 --> 00:35:43,083 some build skyscrapers. 384 00:35:50,200 --> 00:35:53,720 Using mud and feces mixed with saliva, 385 00:35:53,720 --> 00:35:57,233 these mounds tower 10 feet or more above the ground. 386 00:35:58,200 --> 00:36:00,970 On the termite scale, this is nearly double 387 00:36:00,970 --> 00:36:03,593 the height of the world's tallest building, 388 00:36:09,020 --> 00:36:11,223 but this isn't even their nest. 389 00:36:13,060 --> 00:36:15,750 That lies mostly underground. 390 00:36:15,750 --> 00:36:18,010 At the bottom of the tower, 391 00:36:18,010 --> 00:36:20,910 a network of galleries packed with workers 392 00:36:23,290 --> 00:36:28,290 and at the center, the queen, huge, bloated, 393 00:36:29,700 --> 00:36:32,079 just an egg-laying machine. 394 00:36:32,079 --> 00:36:34,996 (mysterious music) 395 00:36:40,530 --> 00:36:43,533 Inside the tower, there's a network of tunnels, 396 00:36:46,090 --> 00:36:47,903 but they're more or less deserted, 397 00:36:48,870 --> 00:36:52,073 just a few maintenance crews repairing any damage. 398 00:36:56,060 --> 00:36:58,500 So why have the termites made such an effort 399 00:36:58,500 --> 00:37:00,633 to build this huge structure? 400 00:37:04,090 --> 00:37:07,600 To answer that we need to see inside the tower, 401 00:37:07,600 --> 00:37:11,590 which we can, using 3D scans that are built 402 00:37:11,590 --> 00:37:14,543 up in the same way as MRI scans. 403 00:37:19,070 --> 00:37:21,820 This is a real termite's nest 404 00:37:21,820 --> 00:37:24,630 as if we could see through the mud walls 405 00:37:24,630 --> 00:37:28,083 to reveal a labyrinth of tunnels inside the mound. 406 00:37:32,307 --> 00:37:34,440 On the side facing the sun, 407 00:37:34,440 --> 00:37:36,803 the air inside the tunnels heats up. 408 00:37:40,500 --> 00:37:44,020 The warm air rises then sinks again, 409 00:37:44,020 --> 00:37:47,013 down through the cooler tunnels on the shady side. 410 00:37:51,130 --> 00:37:53,560 The sun creates a circulation of air 411 00:37:53,560 --> 00:37:55,633 around the inside of the tower. 412 00:38:01,070 --> 00:38:04,230 As the sun tracks across the sky, 413 00:38:04,230 --> 00:38:06,453 it heats different parts of the tower, 414 00:38:07,506 --> 00:38:10,173 so over time, the circulation changes. 415 00:38:17,130 --> 00:38:19,653 The tower is a giant lung. 416 00:38:20,620 --> 00:38:23,103 As the air moves through the tunnels, 417 00:38:24,250 --> 00:38:27,720 stale air leaves the mound through pores in the walls 418 00:38:27,720 --> 00:38:30,060 and fresh air flows in 419 00:38:30,060 --> 00:38:33,373 while the termites all stay safe in their fortress. 420 00:38:41,040 --> 00:38:44,543 But these castles of clay are not entirely secure. 421 00:38:50,830 --> 00:38:54,011 The termites are not alone in the landscape. 422 00:38:54,011 --> 00:38:57,344 (dramatic, tense music) 423 00:39:04,490 --> 00:39:06,630 Not far from the termite mound, 424 00:39:06,630 --> 00:39:09,260 an ancient baobab tree marks the site 425 00:39:09,260 --> 00:39:11,163 of another underground city. 426 00:39:15,170 --> 00:39:16,870 This one belongs to Matabele ants. 427 00:39:19,640 --> 00:39:22,750 And the two greatest insect societies, 428 00:39:22,750 --> 00:39:26,490 the ants and the termites, have been at war with each other 429 00:39:26,490 --> 00:39:29,143 for millions and millions of years. 430 00:39:37,040 --> 00:39:38,923 Matabele ants hunt termites. 431 00:39:39,770 --> 00:39:41,783 And this is a raiding party. 432 00:39:42,775 --> 00:39:46,108 (tense music continues) 433 00:39:54,070 --> 00:39:57,963 The column is following a trail, laid down by their scouts. 434 00:40:03,970 --> 00:40:06,383 And it's heading straight for the termite nest. 435 00:40:26,908 --> 00:40:30,241 (tense music continues) 436 00:40:31,400 --> 00:40:33,363 But this won't be an easy victory. 437 00:40:34,250 --> 00:40:36,420 Termites have well-armed soldiers 438 00:40:39,400 --> 00:40:41,463 and they fight hard to defend their home. 439 00:41:05,580 --> 00:41:07,493 But resistance is futile. 440 00:41:10,320 --> 00:41:13,427 The ants sting the termites in their heads 441 00:41:13,427 --> 00:41:16,213 to paralyze their powerful jaws. 442 00:41:24,200 --> 00:41:26,773 The termites are eventually overrun. 443 00:41:32,159 --> 00:41:35,980 The Matabele ants have also suffered heavy casualties. 444 00:41:38,030 --> 00:41:41,513 In ant colonies workers are normally expendable, 445 00:41:43,400 --> 00:41:45,083 but not in this society. 446 00:41:56,060 --> 00:41:59,383 Many of the ants aren't dead, just wounded. 447 00:42:03,090 --> 00:42:06,773 And Matabele ants practice battlefield triage. 448 00:42:10,090 --> 00:42:12,253 The fallen ants are assessed. 449 00:42:15,040 --> 00:42:17,490 The fatally injured are left to die, 450 00:42:17,490 --> 00:42:19,850 but comrades who were less badly hurt 451 00:42:19,850 --> 00:42:22,023 are medevacked back to the nest. 452 00:42:37,890 --> 00:42:40,677 Other ants bring home the spoils of war. 453 00:42:58,490 --> 00:43:00,200 Back in the nest, 454 00:43:00,200 --> 00:43:02,863 the casualties are treated by their sisters. 455 00:43:05,350 --> 00:43:08,343 And then, even more unexpected, 456 00:43:09,284 --> 00:43:11,010 (gentle music) 457 00:43:11,010 --> 00:43:14,820 these ants produce an antimicrobial secretion 458 00:43:14,820 --> 00:43:18,020 that they smear onto the wounds. 459 00:43:18,020 --> 00:43:19,503 It prevents infection. 460 00:43:22,750 --> 00:43:24,220 And ants treated like this, 461 00:43:24,220 --> 00:43:26,440 more often than not make a good recovery 462 00:43:26,440 --> 00:43:28,143 and live to fight again. 463 00:43:40,130 --> 00:43:43,130 Once insect societies reach this level 464 00:43:43,130 --> 00:43:44,833 they can take the ultimate step. 465 00:43:57,040 --> 00:44:00,950 A queen honeybee never has to face the dangerous challenge 466 00:44:00,950 --> 00:44:03,793 of starting a new colony without any help. 467 00:44:07,060 --> 00:44:09,510 When she leaves the hive, 468 00:44:09,510 --> 00:44:12,283 she's escorted by thousands of workers. 469 00:44:16,140 --> 00:44:18,950 First, they form a temporary home, 470 00:44:18,950 --> 00:44:21,653 a bivouac of living bodies. 471 00:44:21,653 --> 00:44:24,110 (bees buzzing) 472 00:44:24,110 --> 00:44:26,580 Somewhere deep in this swarm, 473 00:44:26,580 --> 00:44:30,293 the queen is protected by a blanket of stinging workers. 474 00:44:36,030 --> 00:44:40,340 Now she's safe, others set out to find a secure hole, 475 00:44:40,340 --> 00:44:42,533 big enough to house the new colony. 476 00:44:49,070 --> 00:44:50,363 A bit run down. 477 00:44:54,130 --> 00:44:55,043 Too small. 478 00:45:04,140 --> 00:45:06,313 But this looks perfect. 479 00:45:13,278 --> 00:45:16,120 The workers report back to the swarm 480 00:45:16,120 --> 00:45:18,193 and tell their sisters the good news, 481 00:45:22,510 --> 00:45:23,503 by dancing. 482 00:45:27,070 --> 00:45:30,440 The famous waggle dance is normally used by a worker 483 00:45:30,440 --> 00:45:33,120 inside the hive to guide her sisters 484 00:45:33,120 --> 00:45:35,163 to a good source of pollen or nectar. 485 00:45:39,030 --> 00:45:42,403 But now the dance gives them directions to their new home. 486 00:45:47,040 --> 00:45:50,440 The worker's dance on the vertical face of the swarm 487 00:45:50,440 --> 00:45:53,610 but their waggle walk isn't straight up or down. 488 00:45:53,610 --> 00:45:57,500 It's at a precise angle to the vertical and that's the angle 489 00:45:57,500 --> 00:46:01,133 to the sun that the other bees will need to fly. 490 00:46:06,070 --> 00:46:07,300 And the distance is given 491 00:46:07,300 --> 00:46:09,183 by the length of the waggle walk. 492 00:46:10,250 --> 00:46:12,113 GPS for bees. 493 00:46:18,080 --> 00:46:20,984 Now the bees all know where they're going. 494 00:46:20,984 --> 00:46:22,970 (bees buzzing) 495 00:46:22,970 --> 00:46:25,060 They can abandon their temporary nest 496 00:46:28,270 --> 00:46:30,660 and decamp to their new permanent home. 497 00:46:44,140 --> 00:46:46,790 But even with such enhanced security 498 00:46:46,790 --> 00:46:48,773 sometimes that's still not enough. 499 00:46:50,975 --> 00:46:53,642 (ominous music) 500 00:47:03,060 --> 00:47:06,533 Asian hornets specialize in hunting honey bees. 501 00:47:16,870 --> 00:47:18,773 Honey bees deploy guards. 502 00:47:19,970 --> 00:47:21,270 They must stop the hornet 503 00:47:21,270 --> 00:47:24,013 storming the hive and destroying the brood. 504 00:47:26,185 --> 00:47:29,685 (ominous music continues) 505 00:47:33,210 --> 00:47:37,093 Some brave souls even face down their giant attackers. 506 00:47:43,550 --> 00:47:46,500 It might look like a no fly zone out there 507 00:47:46,500 --> 00:47:48,530 but the bees have no choice. 508 00:47:48,530 --> 00:47:51,873 They have to leave the hive to find food for the colony. 509 00:47:57,890 --> 00:48:02,463 And that means a dangerous flight through hostile air space. 510 00:48:15,070 --> 00:48:17,813 Some bees are nimble enough to avoid capture. 511 00:48:24,879 --> 00:48:27,462 But many more are not so lucky. 512 00:48:39,080 --> 00:48:41,323 Alarm spreads through the colony. 513 00:48:49,740 --> 00:48:54,423 A narrow escape, but in her panic she misses her landing. 514 00:49:17,250 --> 00:49:19,613 A successful mission bringing in provisions, 515 00:49:20,488 --> 00:49:22,383 but fewer and fewer make it back. 516 00:49:37,740 --> 00:49:40,300 Asian Hornets are so ruthless 517 00:49:40,300 --> 00:49:43,043 they can soon destroy a whole hive. 518 00:49:48,070 --> 00:49:49,160 Honeybees in Europe 519 00:49:49,160 --> 00:49:53,180 didn't have to face this menace until 2004. 520 00:49:53,180 --> 00:49:57,500 When a single queen Asian hornet was accidentally carried 521 00:49:57,500 --> 00:50:01,653 to France, hidden in a shipment of plant pots from China. 522 00:50:05,790 --> 00:50:08,260 And from there, they spread rapidly 523 00:50:08,260 --> 00:50:11,303 to threaten hives across the whole continent. 524 00:50:17,891 --> 00:50:19,920 (somber music) 525 00:50:19,920 --> 00:50:22,730 Simple carelessness threatens the very existence 526 00:50:22,730 --> 00:50:25,323 of one of our oldest insect allies. 527 00:50:28,100 --> 00:50:31,173 Honeybees have been important to humans for millennia. 528 00:50:34,210 --> 00:50:36,450 Before we refined sugar, 529 00:50:36,450 --> 00:50:39,083 their honey was the sweetest thing in our lives. 530 00:50:44,060 --> 00:50:46,370 And now these industrious workers 531 00:50:46,370 --> 00:50:48,453 pollinate many of our crops. 532 00:50:52,160 --> 00:50:54,753 But they're not the only insects we depend on. 533 00:50:57,310 --> 00:50:58,263 Bumblebees. 534 00:51:04,660 --> 00:51:07,620 Hundreds of colonies of bumblebees are employed 535 00:51:07,620 --> 00:51:11,283 pollinating tomatoes in vast commercial greenhouses. 536 00:51:20,920 --> 00:51:24,450 In Queensland, stingless bees are given the job 537 00:51:24,450 --> 00:51:27,133 of pollinating macadamia nut trees. 538 00:51:34,050 --> 00:51:37,720 Even solitary bees, like these alkali bees 539 00:51:37,720 --> 00:51:40,280 can be encouraged to nest in their millions 540 00:51:40,280 --> 00:51:43,223 if farmers create the right soil conditions. 541 00:51:50,100 --> 00:51:52,060 These are bee beds. 542 00:51:52,060 --> 00:51:53,860 And in return for a home 543 00:51:53,860 --> 00:51:56,533 the bees pollinate the alfalfa crops. 544 00:52:05,030 --> 00:52:07,460 Our lives depend on these bees 545 00:52:07,460 --> 00:52:09,453 and many other insects like them. 546 00:52:12,630 --> 00:52:13,670 Around three quarters 547 00:52:13,670 --> 00:52:17,360 of all our crops are pollinated by insects 548 00:52:17,360 --> 00:52:19,840 and yet we're deliberately making their lives 549 00:52:19,840 --> 00:52:21,283 almost impossible. 550 00:52:26,040 --> 00:52:28,990 Bees along with most other insects 551 00:52:28,990 --> 00:52:32,173 are struggling to survive in the world we've created. 552 00:52:35,050 --> 00:52:37,783 Most of the flower-rich meadows have gone. 553 00:52:39,020 --> 00:52:39,853 Plowed under. 554 00:52:44,010 --> 00:52:47,353 The countryside has been drenched in insecticides. 555 00:52:52,030 --> 00:52:55,800 In many parts of the world, insect populations have dropped 556 00:52:55,800 --> 00:52:59,223 by three quarters in just the last few decades. 557 00:53:02,884 --> 00:53:07,040 Vital pollinators like bumblebees are disappearing 558 00:53:07,040 --> 00:53:08,993 across much of their range. 559 00:53:13,050 --> 00:53:15,860 Meadows rich in flowers were once common 560 00:53:15,860 --> 00:53:18,263 but now only a few remain. 561 00:53:27,640 --> 00:53:30,660 Both flowers and insects have been forced to retreat 562 00:53:30,660 --> 00:53:32,463 to the very edge of our world. 563 00:53:34,910 --> 00:53:37,473 Places like the outer Hebrides in Scotland, 564 00:53:40,650 --> 00:53:42,920 where land is still farmed traditionally 565 00:53:42,920 --> 00:53:45,543 and creates a riot of wild flowers. 566 00:53:49,060 --> 00:53:52,460 In Britain, this is now virtually the last refuge 567 00:53:52,460 --> 00:53:55,497 of the most spectacular of all bees: 568 00:53:55,497 --> 00:53:57,383 the great yellow bumblebee. 569 00:54:09,900 --> 00:54:12,750 These remote sanctuaries are the only places 570 00:54:12,750 --> 00:54:16,173 it can find the flowers it needs to feed its family. 571 00:54:27,100 --> 00:54:30,493 The same story is being told all around the world. 572 00:54:32,100 --> 00:54:36,363 Every day we lose untold billions of tiny lives. 573 00:54:43,070 --> 00:54:45,763 Yet insects are amazingly resilient. 574 00:54:47,020 --> 00:54:50,873 They've been around for well over 400 million years. 575 00:54:52,360 --> 00:54:54,580 They even survived the mass extinction 576 00:54:54,580 --> 00:54:56,563 that wiped out the dinosaurs. 577 00:55:02,260 --> 00:55:05,600 If we learn to appreciate them, to value them 578 00:55:06,977 --> 00:55:11,977 and to give them a chance, they'll always repay us. 579 00:55:16,860 --> 00:55:18,453 They are after all, 580 00:55:19,370 --> 00:55:23,875 the little creatures that run the world. 581 00:55:23,875 --> 00:55:26,625 (dramatic music)