The Fascinating World of Spiders | BBC Earth

to help her in her quest she's equipped with three superpowers first an amazing approach to getting about Portia is a jumping spider able to leap up to 50 times her own body length nowhere seems beyond her reach next her second superpower super by sight essential if she's to distinguish her prey in all this clutter because her prey doesn't stray Portia is a spider eating spider this raises a few problems her lunch is three times her size packed with venom and surrounded by a sticky trap mission impossible not at all because of her third superpower Portia is a genius she can map her world in three dimensions and formulate a plan of attack she can have an idea the web builder is blind it won't have a clue that she's coming right on target and safely behind those fangs but a mind as as active as Portia's can always do with more brain food here there's no up a point for the abseil but Portia has another idea instead of going to the spider will bring the spider to her she plucks the strands to imitate struggling prey drawing the spider in for its death it's called Darwin's bark spider and the The female has a remarkable strategy. Like a real-life spider woman, she sprays strands of silk in one long, continuous flow. The threads fan out like a sail and drift on air currents blowing across the water. Every few seconds, she crimps the strands together to stop them spreading too widely. The breeze will do the rest, blowing the threads into a single line and a 25-meter bridge. Now, she must reinforce her bridge because her web will hang from it. But there's something bouncing the line at the other end. Another Darwin spider is trying to take advantage of her hard work. She must deal with the intruder head on. The cut line is an inconvenience, but no more than that. With hooks on the tips of each leg, she gathers the thread. She gathers in the thread. It won't go to waste, as she'll eat it later. When it's all reeled in, she sprays again. Out streams another 25-meter bridging line. How a spider no bigger than a thumbnail can produce so much silk so quickly has baffled scientists. And it's no ordinary silk. It's the toughest natural fiber on the planet, tougher than steel. And it needs to be done. It's tough to span the wide river. With the bridge taut and the ground anchor in place, it's time to construct her trap. These spiders can build the world's largest orb webs, up to two meters wide. A few hours from the first spray of bridging line, the job is done. Now, her strategy is simple. Sit and wait. And there's one final bout of silk production. Shrink around. Wrapping her food for later. That is the weirdest thing I've ever seen in my life. It's a fly. Hasn't got any wings. And it's got these really long legs. George McGavin's great passion is for insects. Strange high legs. At first, I thought it was a cricket, a tiny cricket. But it's a bat fly. Insects make ecosystems work. Without bees, for instance, you'd have no flowering plants. You'd have no vegetables, no fruit. So without the insects, you simply wouldn't have the big animals. From the tiniest bugs to the largest birds, there's over a million known species living in rainforests. George believes there could be another five million still waiting to be discovered. Oh, I say, look at that. Fallen trees like this are an amazing resource for insects and bugs and stuff. They're not always hollow enough to crawl inside. It is big. It is a biggie. This is going to be epic. Now, there's a bat. Look, look, look, look there. See it? There's about three of them. The thing is, there's nothing else in there. That's the worry. And let's go. Let's see what's in here. It's like crawling into a large, peaty tube. It's an extreme habitat, very rarely explored. And straight away, it's coming up against new creatures. This is amazing. Look what we've got here. This is a whip spider. These long bits are actually its front legs. And because it lives in darkness, you can see how it's just feeling my finger there. See? It uses these very long legs to feel its prey. And its prey are these cave crickets here. Very sneakily, sometimes the whip spiders reach behind the cricket and just go tickle, tickle on the back end. And the cricket jumps forward into the jaws of the whip spider, which is a really clever trick. The further I go into this, there's bigger and bigger whip spiders. Oh, there's an absolute. monster over here. There are now, on this part of the roof, 13 crickets and five whip spiders who are just queuing up to eat them like crazy. Little is known about the biology of these weird predators. Somehow, George has to catch one to take it back to the lab. One's just crawled across my face. Because it's now getting really, really tight, I have a bit of a problem. It's as hot as a sauna and crawling with bugs. George is in his element. Ah, ah, just one sec. I can't, I can't get out this, this, this hole's too tight. Ah. Ah, ah, I feel like a, a beetle grub emerging from, from its long period of metamorphosis. Actually, I think I am stuck, actually. All I can say is. I don't think I've had as much fun in a log for a long time. Usually, George only sees these bizarre beasts dead in a museum drawer. It's a rare chance to examine them alive. Isn't that wonderful? That is the ultimate animal for hunting for prey in the dark. It's flattened, it's fast, it's got big, spiky pups at the front end, incredibly long legs for just feeling its prey. If you designed an oracle, you would have to go through it. It's an organism for catching crickets in the dark. This is it. And once the poor animal is trapped in those spines at the front, there is no escape from it. Predators all over the world use the element of disguise to dupe their food. By pretending to be a harmless branch, this African vines snake tricks its prey into thinking they're safe, when they could be about to get eaten. In Hawaii, a fly is in for a shock. From a carnivorous animal. caterpillar in a leafy costume. And while it may look just like an alluring flower, this orchid mantis is a stealthy assassin. But compared to these exceptional masquerades, our spider's disguise is, well, a little rubbish. Its color is a good match. It has a decidedly un-spider-like nip at the waist, just like an ant. But surely no one would mistake one for the other. Nevertheless, it heads for the nest. Will it get away with it? Mission accomplished, and right under the ant's radar. But it wasn't its appearance that did the trick. It's mastered a far more complex impersonation. Our spider carries with it the ant's chemical code. Like all of its kind, it was born in a green ant. Its mother laid her eggs there. It fed on ant larvae from birth and developed the ability to smell just like them. Now that it's essentially hacked into their security, it can rob the nest whenever it likes. Keep an eye out for spiders. In the dark of the forest, George and a team of local trackers are stalking the world's largest tarantula. You're coming this way? Yes. Yeah, bruds, I can see your light. Have you found a new hole? Over. You can see it at the hole. It's there. OK, I'm on my way. Wait there. Oh, my goodness. Terrible as a blonde eye. Like the life of a bird-eating spider. Oh, wow. Great. The trouble with this is, the first fright that she gets and she'll dive into that hole again, and we won't ever be able to get her out. That's OK. That's OK. No, that's fine. I'm going to try a little stick to sort of tease her forward. Now, is there any way you could go round the back and block the hole? Poor sighted, tarantulas hunt by sensing vibrations in the ground. They wait to pounce on passing prey. She is a beauty. That's it. That's it. That's it. Now, these guys don't normally... ..bite as a first defence. They normally flick hairs. And she was flicking hairs. Let's just block that hole. The barbed hairs are designed to irritate a predator's skin, eyes and lungs. Those hairs are extremely irritating. I'm going to cough. Don't let me cough. Because if I cough, she'll get a fright. I'm desperately trying not to cough at the moment. OK, it's gone. Thank God for that. These guys have inch-long fangs. And you really don't want that in your finger. Erm... Oh, dear. Do not cough. But you see how incredibly beautiful she is. She moves serenely. Well, like... Oh, she jumped. There we are. I'm going to try and get her back in the box, only because I want to see how heavy she is. After which, we will bring her back to her hole here. I've got to get back. It's flicked the hairs. They were in the clouds and it's gone on my face, gone up my arm, inside my arms. It's gone up this arm. I've actually inhaled some of them. I'm coughing. Which, of course, shows what an effective way of putting off enemies it is. You know, you don't need inch-long fangs if you can make somebody twitch an itch all over. Ah! The long, tenacious fangs of the Ohia wend their way through the cracks and penetrate deep into the rock in search of trapped water and nutrients. Their quest leads them to a remarkable subterranean world. Once, a raging torrent of lava flowed right through here. When it stopped, this was all that remained. A lava tube. Pitch black. Constantly damp. And very cold. Can anything survive in this harsh world? Amazingly, yes. Patches of bacteria line the walls, feeding on the minerals in the volcanic rock itself. But that's not all. This is the small-eyed, big-eyed hunting spider. A curious name for any spider, let alone one whose eyes barely function. But in total darkness, eyes are little use. Although he can't see it, the spider has company. Rare crickets scale the rocks, while translucent earwigs and milky millipedes forage for food. These are cave specialists, or troglobites, and they never leave the lava tube. Over time, most have lost their eyes and color. Like this plant hopper. Its tail has a curious function. Any predator biting it from behind will be left with nothing but a mouthful of irritating, waxy hair. This is a place of ghostly stillness. A definite advantage for the small-eyed, big-eyed hunting spider. With its super-sensitive leg hairs, it can pick up the slightest movement in the air, and it senses the cricket's presence long before it's close enough to ambush. As prey are few and far between, this may be its last meal for some time. With no light and little vegetation, only the specialists survive here.