Leech vs. Crab: The Most Disturbing Underwater Battle! | Monster Bug Wars

Added: 2026-04-29

[00:00:01]When a house centipede and a swift tree mantid meet to compete, the loser will become the winner's [music] trophy.

[00:00:18]This is a house centipede.

[00:00:23]A lean, mean killer with just three speeds.

[00:00:29]Stopped, fast, and faster. [music] With 30 legs to propel itself, it's the bug equivalent of an Olympic track and field team rolled [music] into one.

[00:00:51]The front legs [music] are relatively short. The hind legs are relatively long, so the legs don't trip over one another as they're running this fast.

[00:01:01]>> [music] >> When the house centipede feels the need for speed, >> [music] >> it covers up to 16 and a half inches of ground every second.

[00:01:14]That's like a human [music] sprinting at 42 mph.

[00:01:22]It's a unique design where even a couple of spare limbs are put to good use.

[00:01:32]The centipede has venom claws. These are evolutionarily modified front legs that are sickle-shaped organs that are extremely flexible and are able to inject venom into the prey, plus help tear it apart.

[00:01:50]But deadly venom and lethal speed are useless unless you can see where you're going.

[00:01:59]These centipedes have huge compound eyes. It's clear that they're using vision to track their prey, and this might be related to the speed at which they're chasing.

[00:02:09]This cockroach would do well to run for its life.

[00:02:15]But you can't outrun a gold medal sprinter.

[00:02:24]House centipedes are incredibly voracious predators.

[00:02:29]They literally run down their prey.

[00:02:36]But the house centipede isn't the only speedy, sharp-eyed predator patrolling the rainforest arena.

[00:02:48]It's also the domain of the swift tree mantid.

[00:02:56]An accomplished all-rounder at blood sports.

[00:03:03]These are a pretty small mantid, only about an inch in length, but they're just as capable as a larger mantid and can punch well above their weight.

[00:03:13]Its opponents are hit with a deadly combination.

[00:03:19]Powerhouse limbs, mean mouthparts, deadly spikes.

[00:03:26]The swift tree mantid is like the leopard of the bug world. It's really well camouflaged, it's fast, and it tears its prey apart with savage bites.

[00:03:39]Thanks to its huge compound eyes, it [music] also has superb vision.

[00:03:47]The swift tree mantid has enormous eyes and incredible visual acuity.

[00:03:55]That's particularly important where both predator and prey are relying on camouflage. If they can pick a prey just standing out a little bit, or a tiny shadow where there shouldn't be a shadow, or little flicker of movement, that can be enough to give the game away.

[00:04:14]The mantid is no slouch at concealing itself, either.

[00:04:19]It's a medal winner when it comes to hide and seek.

[00:04:25]Evolution has resulted in a swift tree having perfect camouflage. Imagine it's like a special forces soldier having a camo suit that allows him to match perfectly the bark [music] that they're on. So just by standing still, they disappear.

[00:04:42]And if their camouflage ever lets them down, they're super fast out of the starting blocks.

[00:04:51]With all the confidence in the world, they leave just about any predator in their wake.

[00:04:59]The swift tree mantid is extremely alert and bold. These guys are quite confident to just brazenly stroll around the smooth bark that doesn't offer any nooks or crannies to hide in. That's because they know they can outrun pretty much any predator that comes by.

[00:05:17]When the swift tree mantid and the house centipede compete for gold, this is winner takes all.

[00:05:35]Deep in the rainforest arena, two cold-blooded killers are about to slug it out for the gold medal in combined blood sports.

[00:05:50]The swift tree mantid might be small, but it's not intimidated.

[00:05:59]The swift tree mantid is extremely alert and bold. It's seemingly unafraid of aggressors, even ones much larger than itself.

[00:06:09]When confronted, it'll stand its ground, holds intimidating-looking poses, give a wicked stare.

[00:06:17]>> [music] >> Is the mantid bold or just plain foolish?

[00:06:23]Its opponent, the house centipede, isn't backing down, either.

[00:06:43]The mantis strikes first.

[00:06:46]It catches the centipede off guard.

[00:06:49]>> [groaning] >> But the bigger centipede counters and stabs the mantid with its venom claws.

[00:07:04]Then starts ripping its victim apart while it's still alive.

[00:07:18]The mantid's insides [music] get sucked up like a sports drink.

[00:07:27]In the bug world, there's only room for one on the winner's podium.

[00:07:37]There are no silver medals.

[00:07:42]Who do their dirty work underwater.

[00:07:47]When a hard-shelled freshwater crab and a slimy tiger leech bump heads, there are no soft options.

[00:08:03]Both creatures live and feed in the same pond.

[00:08:11]But that's where similarities [music] end.

[00:08:15]Both have the will and the weaponry to fight to the finish.

[00:08:22]This pond is simply amazing. It's packed full of life. It has the crabs, it has the leeches, it has small freshwater shrimp. It's got fishes, it's got all sorts of insects living in it. [music] It's an entire active ecosystem. And one of the issues with this sort of a gorgeous little ecosystem is that everyone in this pond runs the constant risk of becoming someone else's dinner.

[00:08:50]The freshwater crab is a shameless scavenger, feeding on the recently dead or anything too weak to fight.

[00:09:01]They'll eat small fish, they'll eat small invertebrates, [music] they'll eat other small crustaceans.

[00:09:08]Uh they'll eat a little bit of plant material. They'll eat essentially anything that they can get.

[00:09:16]Like a knight in shell-hard armor, the freshwater crab's body and legs are safe from all but the most extreme assault.

[00:09:28]Even her eyes retract on stalks, folding in like car side mirrors for safety.

[00:09:38]And serious trauma, like losing a leg, doesn't mean game over.

[00:09:45]Look at this crab. It's missing a leg, it's missing a foot, but it's an arthropod, and because it's an arthropod, it's able to regenerate the leg [music] next time it sheds its exoskeleton.

[00:09:58]Food is always [music] fair game, even when someone else is chewing on it.

[00:10:08]But the freshwater crab's major weapon is its claws.

[00:10:14]And it's with these claws [music] that they're able to do everything. They can grab prey or potential predators. They can tear things apart. They can move rocks around. They can dig burrows.

[00:10:24][music] They do courtship, waving their claws to the females. They can do whatever they want to do.

[00:10:31]>> [music] >> When it comes to defense, crabs are the tanks of the underwater world.

[00:10:45]Crabs have a number of defensive options. One is that they've got these really strong, relatively powerful claws. In addition, they're covered with a very hard exoskeleton.

[00:10:58]They move quite well and can be relatively fast, zipping out of the way.

[00:11:09]Sharing the freshwater pond is a devastating opponent.

[00:11:16]The tiger leech.

[00:11:18]It doesn't feed on the dead.

[00:11:22]It sucks life from the living.

[00:11:25]The tiger leech is an aquatic vampire that actively seeks out its victims. But instead of using fangs, it has three jaws that it makes a Y-shaped incision and then sucks the life out of them.

[00:11:39]The leech breathes through the walls of its body by means of gas exchange. So as long as the water is well oxygenated, it can stay submerged for as long as it likes.

[00:11:49]>> [music] >> These guys are very capable swimmers.

[00:11:51]They're like an eel crossed with a slinky. And once they latch on, the anaconda in them comes out. [music] They really are little monsters.

[00:12:01]Tiger leeches are relentless.

[00:12:08]The posterior sucker attaches to their victims with an almost unbreakable [music] grip.

[00:12:16]Up at the head, the anterior sucker does the real damage.

[00:12:21]It's all mouth with tiny, razor-sharp jaws.

[00:12:31]Once they bite a prey, they hold on with a combination of suction and mucus. They also inject an anti-clotting enzyme to keep the wound from closing up and slowing down their feeding.

[00:12:43]Contrary to popular belief, not all leeches are bloodsuckers.

[00:12:48]Some extract a whole range of bodily fluids.

[00:12:55]Leeches can ingest several times their body weight while feeding off another creature. While this might not be dangerous for a larger animal, for a smaller one, this is lethal, but slow enough that they're fully aware of what's going on.

[00:13:08]If an opponent goes on the attack, the tiger leech has a truly bizarre way of defending itself.

[00:13:18]The tiger leech's best defense is its [music] slime. Its body is actually very difficult for another creature to get a hold of because the mucus it extrudes makes it a very slippery customer.

[00:13:31]That's bad news for the tiny freshwater crab.

[00:13:36]But it does have the weapons to fight back.

[00:13:41]Tiger leeches are tough competitor for these crabs. The leeches are strong and muscular. They're kind of slimy. They're able to move around pretty well.

[00:13:52]However, if the crab is able to grab it with its claw, it it's perfectly capable of cutting it in half. The problem is that the leeches are relatively hard to grab.

[00:14:04]This is a soft, squishy creature versus a well-armed, hard-shelled animal.

[00:14:09]I think the leech is quite capable of bringing the crab down without getting cut to pieces by the claws.

[00:14:17]When a flesh-sucking leech fights a sharp-clawed crab, one is destined for Davy Jones' locker.

[00:14:34]Two pond dwellers are about to engage in a fight to the death.

[00:14:45]One is a flesh-sucking leech, and the other, a hard-shelled crab.

[00:14:53]The crab shell is tough, but the leech's jaws and teeth can cut through it like a diamond-tipped saw.

[00:15:00]That's if the crab doesn't cut the leech in two.

[00:15:09]It's feeding time in the pond, and any creature is fair game.

[00:15:26]The crab backs off, but the leech is back.

[00:15:38]It searches for the crab's Achilles' heel, >> [snorts] >> and finally finds access to the soft flesh.

[00:16:02]The jaws clearly visible, the leech starts to suck the crab dry from the inside.

[00:16:13]This is bad news. The crab is able to defend itself really well on the front of its body, but behind, it can't get its pinchers. It can't get its legs behind it.

[00:16:24]And if that's bad news, there's worse to come.

[00:16:30]Leeches have chemosensory organs, and they've detected a crab in trouble.

[00:16:39]The scent of the crab's blood in the water is like a homing beacon for the pond's other leeches.

[00:16:46]They're going to do everything they can to join the [music] party. And the more that are on board, the less chance the crab has of fighting free.

[00:16:56]Another tiger leech joins the feeding [music] frenzy.

[00:17:01]It latches on.

[00:17:04]The crab grabs with its claws, but the leech is covered with slimy mucus and slips out of the crab's grasp.

[00:17:17]The claws have dispensed with one leech, but now they're gummed with slime.

[00:17:24]Undisturbed, the remaining leech sucks the life out of the crab.

[00:17:34]When the tiger leech drilled through the crab's carapace, the crab began losing all its fluids.

[00:17:39]Emptied of its body fluids, the crab draws its last breath and is consigned to a watery grave.

[00:18:00]The leaf insect has attracted the attention of the mantis.

[00:18:05]And when these two giants of the rainforest come face to face, neither backs down.

[00:18:14]The mantis is the natural aggressor.

[00:18:19]It's sizing up the monster before it.

[00:18:26]No predator wants to be injured by its prey. If it's going to attack, it needs to uh make a trade-off, basically. If it attacks something, is it going to successfully kill it and not get injured itself?

[00:18:44]Beneath the lush rainforest canopy, two giants of the bug world are about to go head-to-head.

[00:18:56]In order to avoid a fight, the spiny leaf insect will actually use its bizarre appearance to try to look like this threatening, horrible alien monster.

[00:19:09]No predator wants to be injured by its prey. So in this case, you've got a really big rainforest mantid, but at the same time, the spiny leaf insect is really quite a large insect.

[00:19:22]The giant rainforest mantis has weighed the options.

[00:19:27]It's only a matter of choosing [music] the moment to strike.

[00:19:31]But with faith in its heavy armor, the spiny leaf insect pushes gamely forward.

[00:19:44]>> [screaming] >> The mantis's powerful jaws start slicing through its victim.

[00:19:57]The heavy armor is holding.

[00:20:02]>> [screaming] >> The spiny leaf insect deploys its chemical weaponry.

[00:20:10]In a fight, spiny leaf insect is going to rely on its armor to hold out long enough for it to get away.

[00:20:17]But it's not very fast. It will, however, keep spraying the chemicals, but unless a predator gets a perfect shot and gets deterred by that, it's only a matter of time until it's dinner.

[00:20:29]The spiny leaf insect has to break free soon before it's devoured.

[00:20:36]Breaching the armor, the more the mantis eats, the less its victim can fight.

[00:20:42]It's a race through the first course.

[00:20:53]Mantis mouth parts work overtime as cutlery.

[00:20:59]Mandibles slice and dice while feelers fork it in.

[00:21:11]Another life ends in the rainforest.

[00:21:17]What the mantis can't eat, others will.

[00:21:25]The giant mantis is happy to share. Now it's full.

[00:21:31]And there's a mess to clean up.