[♪ INTRO] Skull-gathering hunters. Exploding,
toxic defenders. Inflictors of pain. These aren’t characters from a movie:
They’re ants! Normally, we see ants streaming
from cracks in the sidewalk, or coming to forage through our kitchens,
and they’re nothing out of the ordinary. At most, they’re kind of annoying. But some ants are actually amazing, and are a lot cooler and more resourceful
than you might give them credit for. Here are seven of the most extreme species
from around the world. Some people use tapestries and fun knick-knacks
to decorate their homes. But Florida’s skull-collecting ant adorns
its abode with, skulls. Well, more specifically, heads and other dismembered
body parts from other ant species. Which is… a mood, I guess. Scientists discovered this in the 1950s, and
noticed that most of the victims seemed to be trap-jaw ants, which was equally impressive
and alarming, because trap-jaws aren’t easy prey. They’re known for their exceptionally strong
mandibules, which they use to crush their victims and even fling themselves
away from danger. Meanwhile, skull-collecting ants look far
less fearsome. They’re pretty small, and they definitely
don’t have super strong jaws. Researchers were intrigued by how these ants
were adorning their homes with trap-jaw body parts. They weren’t sure if they were actually
killing them, or just inheriting old trap-jaw nests. But recently, they started to figure it out. In November 2018, one researcher published
new findings in the journal of the IUSSI, an organization that studies social insects. By analyzing the chemicals on their bodies
and filming their interactions with trap-jaws, he found that skull-collecting ants chemically
mimic their trap-jaw prey. The difference between their odors is almost
indistinguishable, and that allows the skull collectors to get in close enough to attack. Once they’re in close range, they spray
the trap-jaws with formic acid and paralyze them. Then, they drag their limp bodies back to
their nests, dismember them, and put their exoskeletons on display
like hunting trophies. Researchers aren’t sure why they do this,
but it could be a warning to other ants. And let’s be real: If I were an ant, I wouldn’t
go near that. The Rasberry crazy ant, sometimes called the
tawny crazy ant, originated in South America, but over the last decade, it’s been infiltrating
the U.S. Gulf Coast. These ants are just a few millimeters long,
with long legs and antennas. They’re not known for being aggressive,
and they don’t seem to sting, but they do move around in a really
irregular way when they’re disturbed, which is where their name comes from. It’s not totally clear why they run like
this, but it might be a form of protection. After all, ants scurrying around in a zig-zagging
or looping pattern are harder to smush. Besides their movement, these ants are also
strange because they appear to be drawn to the cooling vents of electrical equipment. So much so that they’ve been known to short out appliances, computers, and even entire chemical plants. Some people believe these insects
are attracted to electricity, but so far, there’s no real
science to support that. Instead, this behavior probably has to do
with chemistry. These ants have been shown to be highly
attracted to each other’s pheromones, or the chemicals their bodies release. So it seems more likely that, when one of
them gets shocked by electrical equipment, probably while looking for a place to nest, they release pheromones that
tell the other ants they’re in danger. Then, thousands of them swarm in the area
to come to the rescue. It’s a much less sci-fi scenario, although
probably no less terrifying for the people who discover a massive ant infestation crawling
around their electronics. They’re not an immediate threat to humans,
but rasberry crazy ants can actually cause major issues for other animals, mainly bees. The ants have been observed destroying hives
and eating bee larvae, which isn’t great when you think about all the other problems
bees are dealing with these days. But at least they’re not stealing body parts. The exploding ant is named after its ability
to explode. At least, in a sense. There are actually a bunch of species that
demonstrate this behavior, but a significant one is called, appropriately, C. explodens. It was identified in a 2018 paper and can
be found throughout Southeast Asia. It may look harmless, with no stinger and
a normal-sized jaw, but don’t be fooled. When some of these exploding ants feel threatened,
you don’t want to be around. First, the ant raises its backside as a warning
to a predator. Then, if the predator is undeterred, the ant,
or a few of them, turns its backside at the predator. They begin to flex as hard as they can until
their abdomens tear open, releasing a bright yellow, sticky toxin that kills the intruder. It sounds kind of horrifying, but it does
protect their colonies. Also, the ants who explode are sterile females,
so this behavior makes a bit more evolutionary sense. If these ants can’t pass along their genes,
at least they’re defending their homes. This research is still pretty recent, and
there are plenty of mysteries surrounding this species, like what that yellow toxin
is made out of, and how the ants optimize their attacks to inflict the most damage. But one thing’s for sure: if an exploding
ant shows you its butt, get outta there. There are over a dozen species in the genus
Polyergus, also called Amazon ants or slave-raiding ants. But they all have similar behavior: They’re
parasites that capture other ant species and put them to work. These ants are spread throughout the world,
but many are found in the U.S. and are known to prey on colonies in the Formica genus. First, an Amazon ant queen will infiltrate
a Formica nest and kill the native queen. But before she can complete her takeover,
she has to be accepted by the colony’s workers. Because, apparently, ants have rules about
this kind of thing. It’s not entirely clear how this acceptance
happens, but it might have something to do with the Amazon ant picking up the old queen’s
scent. Either way, once the Formica ants
have approved their new ruler, the Amazon ants will put them to work. They make the other ants do everything for
them, from cleaning to raising their young. Then, once those babies are grown up, the
Amazon ants move on to the next Formica colony to start the cycle over again. It’s not clear if the Formica ants get
anything out of this relationship, but the Amazon ants definitely do. They even appear to have lost the ability
to take care of their own young altogether, possibly after thousands of years of making
other species do it for them. Bullet ants are known for being the ultimate
pain inducers, and their sting is ranked among the most excruciating of all insect stings. At least, based on something called the Schmidt
Sting Pain Index. It was first published in the
1980s by Justin Schmidt, who actually stung himself
with every species he could find. Which I’m sure sounded like a great idea
at the time. Bullet ants are ranked the highest: a 4-plus. They’re native to the rainforests of Central
and South America, and their bodies are almost creepily long, sometimes approaching three
centimeters in length. Thankfully, they aren’t known for being
aggressive unless you get close to their nests. But once you’ve infringed on their territory,
prepare yourself for a world of pain. What makes their sting so incredibly painful
is a peptide called poneratoxin. It was first described in the early 1990s, and it causes painfully long-lasting
contractions in smooth muscles. Bullet ant encounters are rarely deadly for
humans, but enough stings can cause paralysis and trembling, and the pain can persist for
up to 24 hours. Although these ants are mainly known for the
pain they cause, indigenous peoples have found good uses for them, too, like for closing
wounds. They’ll hold a bullet ant close to the wound
and then, when the ant bites down, twist off its body so that only its pincers remain. It’s not a good time for the ant, but the
venom causes the person’s skin to swell and begins the healing process, making it
easier to keep the wound closed. Resourceful, considering my reaction to bullet
ants would be to run as fast possible in the opposite direction. There are around 40 species of leafcutter
ant spread throughout Central and South America, as well as the U.S. And while they won’t poison you or tear
themselves apart, they are pretty crafty. You might think of ants as stealing crumbs
off your floor, or collecting nectar from plants. But leafcutter ants are farmers. They’re known to slice up pieces of plant
material and carry it back to their nests. Then, they’ll partially digest it and leave
it out to grow their real food: fungus. The fungus can break down compounds in plants
that the ants can’t otherwise digest, and it’s the insects’ main source of nutrients. This fungus is so important that if a queen
starts a new colony, she’ll even take a starter culture to the new home. Leafcutter ants have also been likened to
the pharmacists of the insect world, since they use the antibiotics produced by bacteria
to keep unwanted parasitic fungi from growing. Scientists aren’t sure how that relationship
started, but they know that the bacteria hitches a ride on the outside of the ant, then secretes antibiotics that protect
the health of their precious fungus. All of which seems pretty
complex for a little insect. Finally, speaking of ways ants get their food,
we have honeypot ants. They belong to several genuses and are found
around the world in dry climates like deserts. For the most part, these ants seem pretty
normal, until a drought hits. Among honeypot ants, there’s a special class
of workers called repletes. They feed on things like flower nectar and
dead insects, and their abdomens can swell to enormous sizes, sometimes eight times the
weight of the rest of their bodies. This gives them the appearance of a honeypot,
and you might be able to guess where this is going. During a drought, these ants actually use
this abdominal liquid to keep their fellow colony members alive. To get this sweet substance, another worker
ant will stroke a replete’s antenna, giving them the signal that it’s time to eat. Then, the replete will regurgitate the liquid. Which is amazing, and also kind of horrifying? What makes this even weirder is that honeypot
ants are so bloated with liquid that all they can do is hang from the roofs of nests, waiting
to provide nutrients for their buddies. Like little hanging honey pots, I guess. Unfortunately for the honeypot ants, other
colonies and species of ants have also caught on to this, meaning repletes are easy prey. And in Australia, some indigenous peoples
use them in their diets. But for other ants, they’re basically living
vending machines. Which is so creepy. To most people, ants are nothing special. But like a lot of things in the universe,
you just have to look a little more closely. The ant world is an incredible, dangerous,
and downright bizarre place. And it’s all happening right under your
feet. Thanks for watching this episode of SciShow,
especially to our patrons on Patreon! If you want to support science education online
and help keep us exploring this weird, amazing world we live in, you can go to patreon.com/scishow. [♪ OUTRO]
