1 00:00:00,119 --> 00:00:03,369 (light dramatic music) 2 00:00:25,070 --> 00:00:28,999 Tonight, there's magic in the air. 3 00:00:28,999 --> 00:00:31,499 (light music) 4 00:00:34,610 --> 00:00:37,233 Insects in search of partners. 5 00:00:42,460 --> 00:00:45,403 The world is a very big place, 6 00:00:50,990 --> 00:00:53,433 and insects are very small. 7 00:00:56,060 --> 00:00:57,790 To make more insects, 8 00:00:57,790 --> 00:01:00,203 they somehow have to find each other. 9 00:01:04,070 --> 00:01:07,653 No matter how hard it is or how far. 10 00:01:18,600 --> 00:01:21,380 But they're obviously really good at it. 11 00:01:21,380 --> 00:01:25,183 Insects have been around for hundreds of millions of years. 12 00:01:31,840 --> 00:01:33,180 In that time, 13 00:01:33,180 --> 00:01:36,100 they've evolved all kinds of ingenious ways 14 00:01:36,100 --> 00:01:38,430 to make sure partners get together 15 00:01:42,616 --> 00:01:47,484 and to guarantee the survival of future generations. 16 00:01:47,484 --> 00:01:50,817 (light music continues) 17 00:02:02,824 --> 00:02:05,407 (gulls cawing) 18 00:02:06,730 --> 00:02:09,880 There are a few places on the planet where insects 19 00:02:09,880 --> 00:02:12,907 can really achieve their true potential. 20 00:02:12,907 --> 00:02:15,407 (light music) 21 00:02:19,200 --> 00:02:20,533 Like Mono Lake, 22 00:02:21,560 --> 00:02:24,893 high in the Sierra Nevada Mountains of California. 23 00:02:31,110 --> 00:02:33,640 The water here is so alkaline 24 00:02:33,640 --> 00:02:36,173 not many creatures can survive at all. 25 00:02:38,560 --> 00:02:42,257 But try telling that to one particular kind of insect. 26 00:02:44,156 --> 00:02:47,320 (flies buzzing) 27 00:02:47,320 --> 00:02:51,983 Brine flies, they breed in numbers that defy belief. 28 00:03:02,660 --> 00:03:06,333 They blacken the shores in their hundreds of millions. 29 00:03:06,333 --> 00:03:09,000 (flies buzzing) 30 00:03:16,067 --> 00:03:19,027 And they fill the air with dense clouds. 31 00:03:23,154 --> 00:03:26,128 An all you can eat buffet for the locals. 32 00:03:26,128 --> 00:03:31,128 (gulls cawing) (light dramatic music) 33 00:03:35,886 --> 00:03:40,488 California gulls gorge themselves on clouds of flies. 34 00:03:40,488 --> 00:03:44,571 (light dramatic music continues) 35 00:03:55,190 --> 00:03:58,593 But they make no impact at all on their numbers. 36 00:04:01,673 --> 00:04:03,450 (flies buzzing) 37 00:04:03,450 --> 00:04:06,983 This alien landscape is the realm of insects, 38 00:04:08,110 --> 00:04:10,720 but insects everywhere are very, 39 00:04:10,720 --> 00:04:13,343 very good at making more insects. 40 00:04:18,240 --> 00:04:20,890 Especially when we provide them with five star 41 00:04:20,890 --> 00:04:22,193 board and lodging. 42 00:04:33,901 --> 00:04:37,248 (light dramatic music) 43 00:04:37,248 --> 00:04:40,850 These green bottle fly's eggs will hatch and grow 44 00:04:40,850 --> 00:04:44,753 and transform into pupae in just a few days, 45 00:04:50,140 --> 00:04:53,360 A couple more days and the next generation 46 00:04:53,360 --> 00:04:55,773 is ready to emerge from the pupae. 47 00:05:01,490 --> 00:05:05,763 An inflatable forehead breaks through the tough outer case. 48 00:05:05,763 --> 00:05:08,513 (ominous music) 49 00:05:15,620 --> 00:05:19,373 And these flies are ready to start the whole process again. 50 00:05:20,510 --> 00:05:23,177 (flies buzzing) 51 00:05:27,660 --> 00:05:31,953 Each female can lay 2,000 eggs in her lifetime. 52 00:05:35,090 --> 00:05:38,610 Eggs that will soon turn into more flies that can each lay 53 00:05:38,610 --> 00:05:40,313 2,000 eggs of their own. 54 00:05:46,710 --> 00:05:50,360 If none died, in just two generations, 55 00:05:50,360 --> 00:05:53,233 that's two million flies. 56 00:05:54,800 --> 00:05:57,467 (ominous music) 57 00:06:11,142 --> 00:06:14,610 (flies buzzing) 58 00:06:14,610 --> 00:06:18,400 All insect populations could reach such unimaginable 59 00:06:18,400 --> 00:06:20,550 numbers, but thankfully, 60 00:06:20,550 --> 00:06:22,823 most of their offspring don't survive. 61 00:06:24,750 --> 00:06:27,743 Otherwise we'd all be knee deep in insects. 62 00:06:30,570 --> 00:06:32,593 It's not always this easy. 63 00:06:35,260 --> 00:06:38,160 For many insects, even finding a partner 64 00:06:38,160 --> 00:06:39,773 can be a real problem. 65 00:06:42,560 --> 00:06:45,053 Emperor moths live on open heathland. 66 00:06:48,310 --> 00:06:50,313 The terrain is endless. 67 00:06:53,710 --> 00:06:56,663 The nearest partner could be miles away. 68 00:06:58,720 --> 00:07:03,110 Somehow, two tiny moths must find each other 69 00:07:03,110 --> 00:07:05,973 across a vast featureless landscape. 70 00:07:07,730 --> 00:07:09,340 No problem. 71 00:07:09,340 --> 00:07:11,823 The female moth releases a scent, 72 00:07:12,700 --> 00:07:17,700 a sex pheromone from an organ at the tip of her abdomen. 73 00:07:17,741 --> 00:07:22,741 (light music) (air whooshing) 74 00:07:22,921 --> 00:07:25,490 Caught on the breeze, it drifts down wind 75 00:07:29,020 --> 00:07:32,453 until it's picked up by a sophisticated tracking system; 76 00:07:33,680 --> 00:07:36,200 a male emperor moth's antenna 77 00:07:41,160 --> 00:07:43,030 They're branched like feathers, 78 00:07:43,030 --> 00:07:45,803 which gives them an enormous surface area. 79 00:07:48,220 --> 00:07:50,883 Combining micro x-ray techniques with data 80 00:07:50,883 --> 00:07:53,860 from a scanning electron microscope, 81 00:07:53,860 --> 00:07:57,073 we can see these structures in intricate detail. 82 00:08:00,080 --> 00:08:02,420 They're covered in tiny hairs. 83 00:08:02,420 --> 00:08:06,283 They trap any pheromone molecules wafting past the antennae. 84 00:08:10,130 --> 00:08:13,410 Nerve fibers run inside each hair, 85 00:08:13,410 --> 00:08:16,330 and when a pheromone molecule is trapped on the hair's 86 00:08:16,330 --> 00:08:20,193 surface, it triggers the nerve to fire a signal. 87 00:08:23,100 --> 00:08:25,790 A male moth's antennae can detect 88 00:08:25,790 --> 00:08:28,633 a single molecule of the pheromone. 89 00:08:30,370 --> 00:08:35,097 Sensitive enough to smell a female more than a mile away. 90 00:08:35,097 --> 00:08:37,070 (light music) (birds chirping) 91 00:08:37,070 --> 00:08:40,340 But he doesn't react until he detects more of her scent 92 00:08:41,540 --> 00:08:44,163 until he's certain she's in range. 93 00:08:53,110 --> 00:08:58,110 He flies upwind tracking the scent plume wherever it leads. 94 00:09:01,630 --> 00:09:04,960 Many kinds of insects use sex pheromones, 95 00:09:04,960 --> 00:09:06,710 but each is different. 96 00:09:06,710 --> 00:09:08,750 So each male knows he's tracking 97 00:09:08,750 --> 00:09:10,963 a female of his own species. 98 00:09:15,330 --> 00:09:17,210 The further a male travels, 99 00:09:17,210 --> 00:09:20,090 the stronger the scent becomes. 100 00:09:20,090 --> 00:09:23,573 Triggering more and more hairs on his antennae. 101 00:09:25,410 --> 00:09:30,410 Drawing him further and further upwind towards the source. 102 00:09:36,110 --> 00:09:37,843 A virgin female. 103 00:09:42,100 --> 00:09:43,994 But not for much longer. 104 00:09:43,994 --> 00:09:48,994 (light music continues) (wings rustling) 105 00:09:58,310 --> 00:10:03,310 It all seems so simple, but it's not foolproof. 106 00:10:05,182 --> 00:10:07,932 (birds chirping) 107 00:10:11,250 --> 00:10:14,070 The scent of a female wasp is drifting 108 00:10:14,070 --> 00:10:16,223 through this Australian woodland, 109 00:10:19,800 --> 00:10:22,103 and it's been picked up by a male. 110 00:10:24,040 --> 00:10:27,330 It certainly smells right for his species. 111 00:10:27,330 --> 00:10:30,213 So he sets off on the trail of a female. 112 00:10:32,274 --> 00:10:34,640 (light dramatic music) 113 00:10:34,640 --> 00:10:35,773 Or so he thinks. 114 00:10:39,310 --> 00:10:41,133 But he's going to be disappointed. 115 00:10:44,090 --> 00:10:48,093 The scent is coming from the flower of a wasp orchid. 116 00:10:52,120 --> 00:10:57,120 Still, it definitely smells like a female wasp. 117 00:10:57,240 --> 00:10:58,733 So worth a try. 118 00:11:02,060 --> 00:11:05,880 He tries to mate with the flower, and in his passion, 119 00:11:10,020 --> 00:11:13,713 a packet of the orchid's pollen gets stuck to his back. 120 00:11:17,200 --> 00:11:20,633 Another flower and the poor wasp is fooled again. 121 00:11:27,060 --> 00:11:29,600 This time he scrapes off some of the pollen 122 00:11:34,820 --> 00:11:36,583 and pollinates the flower. 123 00:11:39,570 --> 00:11:41,453 Another successful mating, 124 00:11:42,600 --> 00:11:44,482 but not for the wasp. 125 00:11:44,482 --> 00:11:49,482 (light music continues) (birds chirping) 126 00:11:51,720 --> 00:11:53,620 So maybe there's a more secure way 127 00:11:53,620 --> 00:11:56,543 to send messages over long distances. 128 00:11:59,460 --> 00:12:04,053 Light travels a long way and is easily seen at night. 129 00:12:06,010 --> 00:12:08,740 And it's not at the mercy of the wind 130 00:12:08,740 --> 00:12:10,533 or of deceitful orchids. 131 00:12:12,120 --> 00:12:15,823 (crickets chirping) 132 00:12:15,823 --> 00:12:18,323 (light music) 133 00:12:19,840 --> 00:12:21,970 In their search for romance 134 00:12:21,970 --> 00:12:25,500 some insects put on spectacular light shows. 135 00:12:25,500 --> 00:12:28,833 (light music continues) 136 00:12:32,170 --> 00:12:35,603 Fireflies light up the evening forests. 137 00:12:47,320 --> 00:12:49,790 There might be a dozen or more different kinds 138 00:12:49,790 --> 00:12:53,453 in this one forest, all signaling for a mate. 139 00:12:59,240 --> 00:13:01,650 So, to avoid confusion, 140 00:13:01,650 --> 00:13:05,273 every species needs its own unique code. 141 00:13:09,060 --> 00:13:12,210 Each kind of male flashes at different rates 142 00:13:12,210 --> 00:13:13,943 and at different intervals. 143 00:13:18,400 --> 00:13:22,173 Insects invented morse code long before we did. 144 00:13:26,170 --> 00:13:29,450 When a female sees a pattern she recognizes, 145 00:13:29,450 --> 00:13:32,193 she signals back to identify herself. 146 00:13:37,150 --> 00:13:41,023 And she must also use the correct code for her species. 147 00:13:49,190 --> 00:13:52,130 That way a male knows he's closing in 148 00:13:52,130 --> 00:13:53,463 on one of his own kind. 149 00:13:54,415 --> 00:13:57,748 (light music continues) 150 00:14:04,250 --> 00:14:07,803 The males of some fireflies synchronize their flashing. 151 00:14:09,210 --> 00:14:12,250 Each male is triggered by his neighbors to light his own 152 00:14:12,250 --> 00:14:17,250 lantern and waves of illumination ripple through the forest. 153 00:14:18,527 --> 00:14:21,860 (light music continues) 154 00:14:33,190 --> 00:14:36,023 Seen over the course of the night, 155 00:14:37,510 --> 00:14:40,210 fireflies paint the forest below 156 00:14:42,900 --> 00:14:45,728 and stars paint the sky above. 157 00:14:45,728 --> 00:14:49,061 (light music continues) 158 00:14:57,180 --> 00:15:00,170 Coded signals can also be sent with sound. 159 00:15:00,170 --> 00:15:02,837 (bugs chirping) 160 00:15:06,030 --> 00:15:09,730 After dark, these forests in India are alive 161 00:15:09,730 --> 00:15:12,083 with the love songs of insects. 162 00:15:18,580 --> 00:15:20,733 But this tree cricket has a problem; 163 00:15:23,390 --> 00:15:26,793 to attract a mate, he needs to make himself heard. 164 00:15:28,540 --> 00:15:30,813 To stand out above the din. 165 00:15:39,220 --> 00:15:41,293 Still, he has a plan. 166 00:15:43,090 --> 00:15:47,593 He cuts a hole in the center of a carefully selected leaf. 167 00:15:58,359 --> 00:16:02,609 Then he lines up his wings with the hole and sings. 168 00:16:04,000 --> 00:16:07,083 (crickets chirping) 169 00:16:15,160 --> 00:16:17,640 The leaf works as a baffle. 170 00:16:17,640 --> 00:16:20,580 It stops the sound coming from the rear of his wings 171 00:16:20,580 --> 00:16:24,335 from interfering with the sound coming from the front. 172 00:16:24,335 --> 00:16:27,300 (crickets chirping) 173 00:16:27,300 --> 00:16:29,343 It makes his song much louder, 174 00:16:30,830 --> 00:16:34,483 so it penetrates further through the noisy forest night. 175 00:16:41,560 --> 00:16:43,580 He's one of the very few insects 176 00:16:43,580 --> 00:16:45,453 that have learned to use tools. 177 00:16:46,920 --> 00:16:48,183 And it works. 178 00:16:50,170 --> 00:16:52,863 A female is impressed by his efforts. 179 00:16:56,310 --> 00:16:59,760 After mating, he even offers her dinner; 180 00:16:59,760 --> 00:17:02,610 a secretion from glands between his wings 181 00:17:02,610 --> 00:17:05,013 that are packed with nutritious food. 182 00:17:06,660 --> 00:17:09,833 It will help her produce bigger and better eggs. 183 00:17:10,875 --> 00:17:13,542 (bugs chirping) 184 00:17:15,090 --> 00:17:18,230 It's important for a female to choose the best male 185 00:17:18,230 --> 00:17:20,203 to father the next generation. 186 00:17:21,940 --> 00:17:25,820 For a tree cricket, the volume of the male's song 187 00:17:25,820 --> 00:17:27,290 is a good guide. 188 00:17:27,290 --> 00:17:29,257 (crickets chirping) 189 00:17:29,257 --> 00:17:30,090 (thunder rumbling) 190 00:17:30,090 --> 00:17:33,123 How else can you decide on your perfect partner? 191 00:17:38,170 --> 00:17:41,880 Female stag beetles leave nothing to chance. 192 00:17:41,880 --> 00:17:44,797 (thunder rumbling) 193 00:17:46,899 --> 00:17:49,020 (light dramatic music) 194 00:17:49,020 --> 00:17:53,573 They expect their partners to prove themselves in combat. 195 00:17:56,440 --> 00:18:00,330 Male stag beetles grow their mandibles to sizes out of all 196 00:18:00,330 --> 00:18:04,855 proportion to their bodies, just to impress females. 197 00:18:04,855 --> 00:18:07,855 (suspenseful music) 198 00:18:15,800 --> 00:18:18,440 (light dramatic music) 199 00:18:18,440 --> 00:18:21,170 They use their mandibles like a stag uses 200 00:18:21,170 --> 00:18:24,510 his antlers to fight a duel. 201 00:18:24,510 --> 00:18:27,305 (light dramatic music continues) 202 00:18:27,305 --> 00:18:30,222 (thunder rumbling) 203 00:18:34,160 --> 00:18:35,783 Only winners get to mate, 204 00:18:37,630 --> 00:18:40,740 so evolution has favored ever larger jaws 205 00:18:41,680 --> 00:18:45,851 and bigger heads packed with powerful muscles. 206 00:18:45,851 --> 00:18:49,934 (light dramatic music continues) 207 00:19:07,398 --> 00:19:09,650 And it's not just female beetles that want 208 00:19:09,650 --> 00:19:10,600 to pick the winner. 209 00:19:12,130 --> 00:19:16,297 (woman speaking foreign language) 210 00:19:19,410 --> 00:19:23,560 These fights are so spectacular that across many Asian 211 00:19:23,560 --> 00:19:26,003 countries they've become a kind of sport. 212 00:19:27,556 --> 00:19:30,130 (light dramatic music) 213 00:19:30,130 --> 00:19:32,310 Many of these gladiators are collected 214 00:19:32,310 --> 00:19:34,113 from local rainforests, 215 00:19:35,400 --> 00:19:37,720 but some come from breeders that hope 216 00:19:37,720 --> 00:19:39,693 to raise champion fighters. 217 00:19:44,011 --> 00:19:48,094 (both speaking foreign language) 218 00:19:50,350 --> 00:19:54,683 Bets are placed, sometimes worth a thousand dollars or more. 219 00:19:56,454 --> 00:19:59,704 (light dramatic music) 220 00:20:17,727 --> 00:20:20,810 (suspenseful music) 221 00:20:25,871 --> 00:20:29,538 For the beetles, the loser is the lucky one; 222 00:20:31,040 --> 00:20:33,190 he's returned to the rainforest 223 00:20:34,400 --> 00:20:36,783 while the winner will face another contest. 224 00:20:40,653 --> 00:20:44,140 (light music) (birds chirping) 225 00:20:44,140 --> 00:20:47,743 There are more genteel ways to impress a lady. 226 00:20:57,840 --> 00:21:02,423 In late summer the air is full of the songs of grasshoppers. 227 00:21:05,020 --> 00:21:06,453 Of many different kinds. 228 00:21:07,410 --> 00:21:12,410 (grasshoppers trilling) (light music continues) 229 00:21:14,240 --> 00:21:17,150 Each species sings its own distinct song 230 00:21:17,150 --> 00:21:18,750 in this grassland chorus 231 00:21:20,320 --> 00:21:23,065 to attract females of his own kind. 232 00:21:23,065 --> 00:21:27,620 (grasshoppers trilling) (birds chirping) 233 00:21:27,620 --> 00:21:32,490 But for this rufous grasshopper, a song alone isn't enough. 234 00:21:32,490 --> 00:21:35,543 He needs to perform a whole song and dance routine. 235 00:21:49,110 --> 00:21:51,830 His black and white tipped antennae 236 00:21:51,830 --> 00:21:54,950 and his conspicuous mouth parts are all part 237 00:21:54,950 --> 00:21:56,633 of his dance regalia. 238 00:21:58,226 --> 00:22:01,559 (grasshoppers trilling) 239 00:22:03,250 --> 00:22:05,513 First a twirl with his mouth parts. 240 00:22:17,500 --> 00:22:19,343 Then a bow with his antennae. 241 00:22:20,779 --> 00:22:24,112 (grasshoppers trilling) 242 00:22:30,940 --> 00:22:33,780 The female is obviously impressed. 243 00:22:33,780 --> 00:22:35,473 She sings her own song, 244 00:22:40,690 --> 00:22:43,083 and its meaning is pretty obvious. 245 00:22:50,500 --> 00:22:53,904 (bottle popping) 246 00:22:53,904 --> 00:22:58,904 (light music) (birds chirping) 247 00:23:01,050 --> 00:23:05,533 Dancing is all the more effective with flamboyant costumes. 248 00:23:12,110 --> 00:23:15,300 In the rainforests of Central America 249 00:23:15,300 --> 00:23:18,880 both sexes of the paddle-legged mosquito 250 00:23:18,880 --> 00:23:22,143 wear sparkling blue plumes on their legs. 251 00:23:31,090 --> 00:23:33,770 When a male lands close to a female, 252 00:23:33,770 --> 00:23:37,007 he waves his colorful legs to impress her. 253 00:23:54,370 --> 00:23:58,210 If she likes what she sees, she invites him to mate. 254 00:24:00,260 --> 00:24:03,593 (light music continues) 255 00:24:24,409 --> 00:24:28,750 Then the female leaves him to find a tree hole 256 00:24:28,750 --> 00:24:30,023 filled with water. 257 00:24:32,320 --> 00:24:36,050 She flicks her eggs inside one at a time 258 00:24:37,410 --> 00:24:39,483 with thoughtless accuracy, 259 00:24:46,380 --> 00:24:48,870 Some insects can't afford to waste time 260 00:24:48,870 --> 00:24:50,703 on a romantic courtship. 261 00:24:52,407 --> 00:24:54,907 (light music) 262 00:24:58,740 --> 00:25:02,363 A male ivy bee, and he has a problem. 263 00:25:05,320 --> 00:25:08,053 Female ivy bees only mate once, 264 00:25:09,280 --> 00:25:11,303 so he's going to have to look sharp. 265 00:25:14,120 --> 00:25:16,990 The trouble is there are rival males 266 00:25:16,990 --> 00:25:20,614 emerging all around him. 267 00:25:20,614 --> 00:25:23,197 (bees buzzing) 268 00:25:25,240 --> 00:25:29,463 Male ivy bees emerge from their burrows before the females. 269 00:25:32,300 --> 00:25:35,540 And soon the air is full of hopeful bees 270 00:25:36,500 --> 00:25:40,015 all waiting to spot the first female. 271 00:25:40,015 --> 00:25:42,375 (bees buzzing) 272 00:25:42,375 --> 00:25:44,875 (light music) 273 00:26:01,220 --> 00:26:02,963 When a female does emerge, 274 00:26:06,060 --> 00:26:10,510 she's pounced on by dozens of eager males 275 00:26:10,510 --> 00:26:12,293 all desperate to mate. 276 00:26:12,293 --> 00:26:17,293 (dramatic music) (bees buzzing) 277 00:26:17,330 --> 00:26:21,930 In their frenzy these bees form mating balls. 278 00:26:21,930 --> 00:26:24,603 Sometimes of dozens of male bees. 279 00:26:27,998 --> 00:26:30,790 And somewhere inside the creche, a female. 280 00:26:48,380 --> 00:26:51,470 Eventually, one lucky male wins, 281 00:26:51,470 --> 00:26:52,713 usually the biggest. 282 00:26:53,645 --> 00:26:55,090 (bees buzzing) 283 00:26:55,090 --> 00:26:58,053 The female didn't have to work too hard to find a mate. 284 00:26:59,170 --> 00:27:03,433 All she had to do was to stick her head above ground. 285 00:27:05,110 --> 00:27:09,840 But now she has to dig herself a nest burrow all on her own 286 00:27:10,700 --> 00:27:14,563 while the males hang around for their next opportunity. 287 00:27:15,555 --> 00:27:20,460 (bees buzzing) (birds chirping) 288 00:27:20,460 --> 00:27:23,390 Having a big get together like this certainly makes 289 00:27:23,390 --> 00:27:25,653 finding a partner a lot easier, 290 00:27:26,730 --> 00:27:28,970 but sometimes even the biggest gatherings 291 00:27:28,970 --> 00:27:30,703 still face problems. 292 00:27:34,340 --> 00:27:36,603 The River Danube in Hungary. 293 00:27:39,760 --> 00:27:43,280 These mayflies have spent a year on the bottom of the river 294 00:27:43,280 --> 00:27:46,930 feeding and now they emerge from the water 295 00:27:48,480 --> 00:27:50,207 and turn into adults. 296 00:27:50,207 --> 00:27:52,707 (light music) 297 00:27:54,090 --> 00:27:57,667 They'll only live for this one night, but what a night. 298 00:28:04,340 --> 00:28:09,191 As dusk falls, an insect orgy begins. 299 00:28:09,191 --> 00:28:12,524 (light music continues) 300 00:28:17,244 --> 00:28:20,744 Millions of mayflies dance over the river. 301 00:28:22,280 --> 00:28:26,143 Their only purpose is to breed and make more mayflies. 302 00:28:30,280 --> 00:28:32,450 Mayflies have been around since before 303 00:28:32,450 --> 00:28:34,313 the time of the dinosaurs, 304 00:28:35,680 --> 00:28:38,713 but today they face a very modern problem. 305 00:28:41,350 --> 00:28:43,880 Bright lights on bridges over the river 306 00:28:43,880 --> 00:28:46,383 draw them away from their dances. 307 00:28:51,380 --> 00:28:53,743 It's a blizzard of mayflies. 308 00:28:57,690 --> 00:29:00,900 Many crash onto the road and will die here 309 00:29:01,850 --> 00:29:04,313 without ever getting a chance to breed. 310 00:29:06,222 --> 00:29:11,222 (traffic humming) (light music) 311 00:29:14,098 --> 00:29:15,380 In the last few years, 312 00:29:15,380 --> 00:29:17,720 even brighter lights have been installed 313 00:29:19,040 --> 00:29:20,363 below the bridges. 314 00:29:23,500 --> 00:29:26,023 Now the mayflies are drawn to these, 315 00:29:33,370 --> 00:29:36,230 but the new lights have been specially designed to keep 316 00:29:36,230 --> 00:29:39,360 the mayflies over the river where 317 00:29:39,360 --> 00:29:41,333 they can fulfill their life's mission. 318 00:29:42,244 --> 00:29:44,827 (light music) 319 00:29:51,180 --> 00:29:54,870 After mating, females dip onto the water's surface 320 00:29:54,870 --> 00:29:56,310 to release their eggs. 321 00:30:07,120 --> 00:30:12,033 Eventually, exhausted, they can no longer take off again. 322 00:30:13,150 --> 00:30:16,760 They've only been adults for a few brief hours, 323 00:30:16,760 --> 00:30:18,023 but their job is done. 324 00:30:22,440 --> 00:30:24,890 Billions of eggs sink to the riverbed 325 00:30:26,110 --> 00:30:29,983 where they'll soon hatch into the next generation of larvae. 326 00:30:35,060 --> 00:30:38,470 For most insects, reproduction simply depends 327 00:30:38,470 --> 00:30:40,494 on huge numbers. 328 00:30:40,494 --> 00:30:44,590 (car horn honking) (traffic humming) 329 00:30:44,590 --> 00:30:46,953 Lay hundreds or thousands of eggs, 330 00:30:48,000 --> 00:30:52,808 abandon them to their fate, and hope a few survive. 331 00:30:52,808 --> 00:30:56,308 (dramatic rhythmic music) 332 00:31:00,440 --> 00:31:03,560 This female vapourer moth is nothing more 333 00:31:03,560 --> 00:31:05,423 than a bag of eggs. 334 00:31:09,150 --> 00:31:13,643 She has no wings and only lives long enough to lay her eggs. 335 00:31:16,300 --> 00:31:19,800 But insects can improve the odds for the next generation 336 00:31:21,240 --> 00:31:24,063 by being careful where they lay their eggs. 337 00:31:29,000 --> 00:31:32,670 A lackey moth arranges hers in a precise band 338 00:31:32,670 --> 00:31:35,530 around a twig of the bush she knows 339 00:31:35,530 --> 00:31:37,163 her caterpillars will eat. 340 00:31:49,080 --> 00:31:51,040 A large white butterfly stacks 341 00:31:51,040 --> 00:31:53,930 hers neatly under a cabbage leaf; 342 00:31:53,930 --> 00:31:56,023 her caterpillar's favorite food. 343 00:32:11,120 --> 00:32:14,410 This Necroscia stick insect makes sure no one 344 00:32:14,410 --> 00:32:16,333 will ever find her eggs. 345 00:32:17,370 --> 00:32:21,153 She holds each huge egg at the tip of her abdomen. 346 00:32:23,060 --> 00:32:27,603 It looks as tough as nails and that's exactly how it's used. 347 00:32:31,100 --> 00:32:34,443 The stick insect hammers it into the trunk of a tree. 348 00:32:40,050 --> 00:32:44,640 Once she's made a dent, she screws the egg into the wood 349 00:32:49,130 --> 00:32:50,993 until it's completely hidden. 350 00:32:57,320 --> 00:33:00,550 A green lacewing has an even more ingenious way 351 00:33:00,550 --> 00:33:01,943 of hiding her eggs. 352 00:33:08,110 --> 00:33:11,840 She lays each one onto the end of a strand of silk 353 00:33:14,080 --> 00:33:16,613 so they aren't noticed by marauding ants. 354 00:33:22,400 --> 00:33:26,323 The eggs themselves are like mini survival capsules. 355 00:33:27,270 --> 00:33:29,210 Magnified a hundred times 356 00:33:30,310 --> 00:33:32,483 they're exquisitely engineered. 357 00:33:33,550 --> 00:33:36,823 Reinforced with struts and braces for strength. 358 00:33:40,090 --> 00:33:43,370 Inside this egg of a large white butterfly, 359 00:33:43,370 --> 00:33:46,253 a tiny caterpillar is developing and growing. 360 00:33:50,100 --> 00:33:52,967 In less than a week it fills the whole egg. 361 00:33:58,090 --> 00:34:03,023 Its soon so big it has to fold in half just to fit inside. 362 00:34:06,760 --> 00:34:08,793 Now it's time to hatch. 363 00:34:18,250 --> 00:34:22,387 When they emerge, most young insects are on their own. 364 00:34:23,245 --> 00:34:25,665 (light music) 365 00:34:25,665 --> 00:34:28,998 (light dramatic music) 366 00:34:42,240 --> 00:34:44,013 They might look tiny and frail, 367 00:34:46,730 --> 00:34:49,400 but they have plenty of tricks to help them survive 368 00:34:49,400 --> 00:34:51,103 in the big, bad world. 369 00:35:00,160 --> 00:35:04,595 If you're a caterpillar, try not to look like a tasty grub. 370 00:35:04,595 --> 00:35:07,095 (light music) 371 00:35:11,580 --> 00:35:14,683 Spines and hairs put off some predators, 372 00:35:23,140 --> 00:35:26,423 but some take the whole disguise thing to extremes. 373 00:35:31,260 --> 00:35:33,463 These really are caterpillars. 374 00:35:41,310 --> 00:35:44,643 A lot of the time young insects do just fine, 375 00:35:47,380 --> 00:35:51,433 but not all insect parents are so remiss. 376 00:35:53,130 --> 00:35:55,853 Some go to a lot more effort. 377 00:36:00,140 --> 00:36:04,010 In North America, this wasp is busy digging out 378 00:36:04,010 --> 00:36:06,193 a burrow to serve as a nest. 379 00:36:11,570 --> 00:36:13,920 Once it's finished, she'll stock it 380 00:36:13,920 --> 00:36:17,343 with a lifetime supply of food for her larva. 381 00:36:25,320 --> 00:36:28,403 These wasps are called cicada killers. 382 00:36:29,635 --> 00:36:32,968 (light dramatic music) 383 00:36:34,650 --> 00:36:37,243 So it's no surprise she hunts cicadas. 384 00:36:39,650 --> 00:36:41,113 But she's not a killer. 385 00:36:49,250 --> 00:36:52,513 She stings them with a venom that paralyzes them. 386 00:36:56,040 --> 00:36:59,070 They won't die, not just yet. 387 00:36:59,070 --> 00:37:00,923 They'll stay nice and fresh, 388 00:37:01,880 --> 00:37:03,913 but they can't escape their fate. 389 00:37:08,150 --> 00:37:11,163 They'll be eaten alive by a wasp grub. 390 00:37:13,100 --> 00:37:16,603 Each larva will need several cicadas to sustain it, 391 00:37:18,140 --> 00:37:20,733 and each nest contains several larvae. 392 00:37:24,080 --> 00:37:28,130 So she has plenty of work to do ferrying cicadas 393 00:37:28,130 --> 00:37:29,383 back to the burrow. 394 00:37:35,100 --> 00:37:37,400 She can even fly with her prey, 395 00:37:37,400 --> 00:37:40,280 even though it might weigh twice as much as she does. 396 00:37:51,120 --> 00:37:55,690 When she's finished, the undead cicadas are sealed 397 00:37:55,690 --> 00:37:57,493 in what will become their tomb. 398 00:37:59,585 --> 00:38:02,335 (dramatic music) 399 00:38:09,150 --> 00:38:13,723 And she starts the whole exhausting task over again. 400 00:38:15,879 --> 00:38:17,870 (light music) 401 00:38:17,870 --> 00:38:21,690 Half a world away, on the plains of Africa, 402 00:38:21,690 --> 00:38:24,840 the big things are busy providing more opportunities 403 00:38:24,840 --> 00:38:26,263 for the little things. 404 00:38:37,766 --> 00:38:40,100 (light dramatic music) 405 00:38:40,100 --> 00:38:44,573 Adult dung beetles feast on dung, and so do their lavae. 406 00:38:51,160 --> 00:38:53,520 And this pile is plenty to feed both 407 00:38:53,520 --> 00:38:55,913 the beetles and their next generation. 408 00:38:57,100 --> 00:39:00,163 But it's not the endless feast that it might look. 409 00:39:03,200 --> 00:39:06,283 There's a mad scramble for any fresh offering. 410 00:39:09,110 --> 00:39:12,043 What's needed is a way to avoid the crush. 411 00:39:16,090 --> 00:39:18,900 Each beetle parcels up dung into a ball 412 00:39:18,900 --> 00:39:21,580 that can be rolled away from the crowd 413 00:39:21,580 --> 00:39:23,313 to a more secluded spot. 414 00:39:33,040 --> 00:39:35,770 To avoid going round in circles, 415 00:39:35,770 --> 00:39:38,693 a dung beetle uses the sun as a compass, 416 00:39:39,580 --> 00:39:42,773 even compensating for its passage across the sky. 417 00:39:46,170 --> 00:39:49,573 In this way, it follows as straight a line as possible. 418 00:39:53,860 --> 00:39:56,650 This male is joined by a female who follows him 419 00:39:56,650 --> 00:39:58,573 and his precious ball of dung. 420 00:40:03,570 --> 00:40:05,420 And they keep going through the night 421 00:40:07,100 --> 00:40:08,943 using the Milky Way as a guide. 422 00:40:18,470 --> 00:40:21,230 Eventually, the two beetles bury the ball 423 00:40:21,230 --> 00:40:22,703 and she lays an egg. 424 00:40:26,150 --> 00:40:29,230 The female stays with the ball to keep the grub growing 425 00:40:29,230 --> 00:40:31,293 insides safe from harm. 426 00:40:33,736 --> 00:40:35,290 (birds chirping) 427 00:40:35,290 --> 00:40:37,760 Across the plains of Africa, 428 00:40:37,760 --> 00:40:40,950 game herds are converting plants into food 429 00:40:40,950 --> 00:40:43,803 for many different kinds of dug beetles. 430 00:40:45,457 --> 00:40:47,810 (light dramatic music) 431 00:40:47,810 --> 00:40:50,670 And antelope dung comes in neatly packaged, 432 00:40:50,670 --> 00:40:53,740 handy, rollable balls. 433 00:40:53,740 --> 00:40:56,870 So convenient that this dung beetle specializes 434 00:40:56,870 --> 00:40:59,493 in burying antelope dung for its larvae. 435 00:41:06,120 --> 00:41:08,923 But sadly, this beetle's been duped. 436 00:41:10,010 --> 00:41:12,163 He's not rolling dung at all. 437 00:41:16,340 --> 00:41:20,670 The seeds of this South African plant look and smell exactly 438 00:41:20,670 --> 00:41:22,053 like antelope dung. 439 00:41:23,760 --> 00:41:26,440 Enough to convince a dung beetle to roll 440 00:41:26,440 --> 00:41:28,113 them away from the plant. 441 00:41:30,170 --> 00:41:33,910 The seeds are rock hard and will provide no sustenance 442 00:41:33,910 --> 00:41:34,843 for its larvae, 443 00:41:36,240 --> 00:41:38,750 but the beetles are so completely fooled 444 00:41:38,750 --> 00:41:41,113 that they bury the plant seeds anyway. 445 00:41:42,460 --> 00:41:45,056 The perfect little gardeners. 446 00:41:45,056 --> 00:41:49,130 (light dramatic music) (wind whistling) 447 00:41:49,130 --> 00:41:52,363 Some dung beetles have abandoned dung altogether. 448 00:41:55,900 --> 00:41:59,440 This species feeds its young on millipede flesh, 449 00:41:59,440 --> 00:42:00,340 which is a problem 450 00:42:02,130 --> 00:42:05,393 because it can't kill a millipede by itself. 451 00:42:14,100 --> 00:42:16,562 It needs to hire an assassin. 452 00:42:16,562 --> 00:42:19,562 (suspenseful music) 453 00:42:25,400 --> 00:42:28,083 Millipede assassin bugs. 454 00:42:32,903 --> 00:42:35,653 (dramatic music) 455 00:42:43,130 --> 00:42:47,310 Assassin bugs even work together to overpower 456 00:42:47,310 --> 00:42:49,173 a really big millipede. 457 00:42:54,251 --> 00:42:57,251 (suspenseful music) 458 00:43:00,610 --> 00:43:03,363 They stab it with their sharp mouth parts, 459 00:43:07,330 --> 00:43:10,283 then they injected with fast acting lethal toxins. 460 00:43:20,140 --> 00:43:22,170 Once they've finished, 461 00:43:22,170 --> 00:43:24,763 there's still plenty left for the beetle family. 462 00:43:33,220 --> 00:43:36,880 It uses its webbed shaped head and powerful legs 463 00:43:36,880 --> 00:43:40,273 to separate the millipede into convenient chunks; 464 00:43:41,860 --> 00:43:45,463 small enough to bury, but big enough to feed its larvae. 465 00:43:47,654 --> 00:43:50,790 (light dramatic music) 466 00:43:50,790 --> 00:43:55,123 And maybe a little bit more appetizing than dung. 467 00:43:58,688 --> 00:44:02,000 (light music) (birds chirping) 468 00:44:02,000 --> 00:44:05,093 Family life among insects takes on many forms. 469 00:44:12,070 --> 00:44:14,240 There are even tender moments happening 470 00:44:14,240 --> 00:44:16,106 right under our feet. 471 00:44:16,106 --> 00:44:18,773 (ominous music) 472 00:44:24,860 --> 00:44:27,943 The common earwig is a model parent. 473 00:44:31,400 --> 00:44:33,313 Mother tends the eggs, 474 00:44:34,580 --> 00:44:39,580 cleaning them and keeping them free from mold and infection. 475 00:44:51,090 --> 00:44:53,950 She sits with them like a bird on the nest, 476 00:44:53,950 --> 00:44:58,383 protecting them from danger like centipedes. 477 00:45:05,230 --> 00:45:09,823 And if anything threatens her clutch, she'll defend them. 478 00:45:11,094 --> 00:45:14,344 (light dramatic music) 479 00:45:16,680 --> 00:45:18,183 She's having none of it. 480 00:45:21,340 --> 00:45:23,763 Her sharp pincers soon see it off. 481 00:45:30,720 --> 00:45:33,373 But just to make sure her clutch is safe, 482 00:45:34,290 --> 00:45:39,290 she now moves her eggs, one by one, to a quieter spot. 483 00:45:45,533 --> 00:45:48,783 (light dramatic music) 484 00:45:53,651 --> 00:45:57,180 (birds chirping) 485 00:45:57,180 --> 00:46:00,100 Thorn bugs raise their families out in the open 486 00:46:00,100 --> 00:46:02,123 where it's even more dangerous. 487 00:46:13,350 --> 00:46:15,713 Mother stands guard over her brood. 488 00:46:17,190 --> 00:46:19,113 She has to be really alert. 489 00:46:22,536 --> 00:46:24,160 (ominous music) 490 00:46:24,160 --> 00:46:27,630 The biggest threats to her family are predatory wasps 491 00:46:29,090 --> 00:46:32,240 always on the lookout for fresh meat. 492 00:46:32,240 --> 00:46:35,740 (ominous music continues) 493 00:46:47,070 --> 00:46:49,030 If the family senses danger, 494 00:46:49,030 --> 00:46:54,030 they drum on the twig by jumping up and down all together. 495 00:47:05,100 --> 00:47:08,283 Their mother responds immediately to their distress call. 496 00:47:11,060 --> 00:47:12,985 First, a warning. 497 00:47:12,985 --> 00:47:15,720 (wings rustling) 498 00:47:15,720 --> 00:47:16,633 A wing buzz. 499 00:47:17,613 --> 00:47:20,160 (light dramatic music) 500 00:47:20,160 --> 00:47:22,325 Back off or else. 501 00:47:22,325 --> 00:47:24,992 (wings buzzing) 502 00:47:29,000 --> 00:47:31,173 She's armed with a sharp thorn, 503 00:47:35,690 --> 00:47:37,790 but that's not her most impressive weapon. 504 00:47:41,479 --> 00:47:44,812 (light dramatic music) 505 00:47:55,114 --> 00:47:57,864 She's a highly skilled kickboxer. 506 00:48:02,020 --> 00:48:06,936 She draws her leg back and kicks. 507 00:48:06,936 --> 00:48:09,686 (dramatic music) 508 00:48:17,190 --> 00:48:20,520 It's so fast that even slowed down 40 times 509 00:48:20,520 --> 00:48:22,523 the action is just a blur. 510 00:48:24,081 --> 00:48:26,050 (dramatic music) 511 00:48:26,050 --> 00:48:28,120 She hits with such a powerful blow 512 00:48:29,700 --> 00:48:31,623 she leaves the wasp reeling. 513 00:48:35,470 --> 00:48:37,233 If she wasn't so vigilant, 514 00:48:39,250 --> 00:48:42,223 predators would soon eat her entire family. 515 00:48:45,960 --> 00:48:48,680 But there is a way to avoid all this stress 516 00:48:51,120 --> 00:48:54,033 and still make sure your babies are well protected; 517 00:48:58,680 --> 00:49:00,143 employ babysitters. 518 00:49:03,330 --> 00:49:06,913 Or, in the case of imperial blue hair streaks, 519 00:49:08,120 --> 00:49:10,090 more like a well armed security force 520 00:49:16,150 --> 00:49:17,993 of rainbow ants. 521 00:49:22,280 --> 00:49:25,880 These butterflies can even recognize the right species 522 00:49:25,880 --> 00:49:29,540 of ant and won't lay eggs on trees 523 00:49:29,540 --> 00:49:31,813 without the right babysitters. 524 00:49:33,952 --> 00:49:36,170 (light dramatic music) (bugs trilling) 525 00:49:36,170 --> 00:49:38,410 As soon as they're laid, the eggs 526 00:49:38,410 --> 00:49:41,580 have ant guards standing over them. 527 00:49:41,580 --> 00:49:44,530 And once they hatch, the caterpillars are never 528 00:49:44,530 --> 00:49:47,643 without an ant escort wherever they go. 529 00:49:50,350 --> 00:49:53,343 But the ants don't provide this service for free. 530 00:49:55,620 --> 00:49:59,770 The caterpillars have special organs that produce food 531 00:49:59,770 --> 00:50:02,513 packed with essential nutrients for the ants. 532 00:50:11,100 --> 00:50:13,570 In return, the ants defend the caterpillars 533 00:50:13,570 --> 00:50:16,801 against any other insects that come too close. 534 00:50:16,801 --> 00:50:20,051 (light dramatic music) 535 00:50:47,230 --> 00:50:51,363 Even when they turn into pupae they still produce ant food, 536 00:50:52,430 --> 00:50:54,663 so the ants continue to guard them. 537 00:50:56,030 --> 00:50:59,800 Imperial blues can pupate out in the open 538 00:50:59,800 --> 00:51:03,623 and in big groups thanks to their guards. 539 00:51:05,470 --> 00:51:07,420 And when they emerge, 540 00:51:07,420 --> 00:51:10,460 the butterflies don't have far to look 541 00:51:10,460 --> 00:51:12,343 for willing babysitters. 542 00:51:14,891 --> 00:51:17,190 (light dramatic music) 543 00:51:17,190 --> 00:51:19,770 But the earwig has to face the trials 544 00:51:19,770 --> 00:51:22,083 of parenthood on her own. 545 00:51:29,140 --> 00:51:30,863 She's more than up to it. 546 00:51:31,860 --> 00:51:34,783 Her maternal instinct is as powerful as any. 547 00:51:41,120 --> 00:51:43,923 She puts everything into raising her family, 548 00:51:44,970 --> 00:51:48,815 even though earwig toddlers can be quite a handful. 549 00:51:48,815 --> 00:51:52,898 (light dramatic music continues) 550 00:51:56,100 --> 00:51:58,080 If they stray too far, 551 00:51:58,080 --> 00:52:00,310 she gently coaxes them back home 552 00:52:00,310 --> 00:52:02,033 with touches from her antennae. 553 00:52:06,670 --> 00:52:11,193 She even carries them like a tiny cat with its kittens. 554 00:52:12,658 --> 00:52:16,741 (light dramatic music continues) 555 00:52:19,170 --> 00:52:22,310 And she feeds them on predigested food 556 00:52:22,310 --> 00:52:25,953 until they're old enough to venture into the big wide world. 557 00:52:33,640 --> 00:52:37,733 It's a touching sight, such a gentle mother. 558 00:52:42,090 --> 00:52:46,140 She's just one example of the ingenious ways that insects 559 00:52:46,140 --> 00:52:48,880 have evolved to make sure the next generation 560 00:52:49,730 --> 00:52:52,484 have the best start in life. 561 00:52:52,484 --> 00:52:54,984 (light music) 562 00:52:57,120 --> 00:53:00,970 They've been producing generation after generation like this 563 00:53:00,970 --> 00:53:04,173 for well over 400 million years. 564 00:53:06,070 --> 00:53:09,670 Over that time they've turned planet earth 565 00:53:09,670 --> 00:53:11,430 into planet insect 566 00:53:13,420 --> 00:53:16,980 thanks to the unparalleled ability of insects 567 00:53:16,980 --> 00:53:18,993 to make more insects. 568 00:53:18,993 --> 00:53:22,326 (light music continues) 569 00:53:55,997 --> 00:53:59,330 (light dramatic music)