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  • Ants are one of the most abundant organisms on land.

  • They're found practically everywhere.

  • But not everything that looks or acts like an ant/is an ant.

  • They'reant-posters.

  • Charlat-ants.

  • Ant mimics.

  • Mimicry is a pretty common ecological phenomenon,

  • and it works in a lot of different ways.

  • Sometimes it's defensive, sometimes aggressive.

  • Sometimes it's all about how you look,

  • and sometimes it's all about how you act.

  • There are a bunch of different kinds of mimicry,

  • and most of them don't have hard and fast lines between them.

  • But these creatures have mastered practically all of them --

  • in order to look like ants.

  • To start off with, let's take a look at the jumping spider Myrmarachne.

  • Instead of the usual squat and stout form a jumping spider might take,

  • these little guys have evolved some extreme body modifications.

  • They've turned super long and skinny, all the better to mimic an ant.

  • The males of some species take it even further,

  • evolving mouth-parts large enough to resemble a worker carrying cargo.

  • They're so big, in fact, that the spider can't get venom through its fangs anymore.

  • This kind of body modification is impressive,

  • but also not super uncommon when dealing with ant mimics.

  • There's even a name for this phenomenon:

  • the Scrabble-winning word myrmecomorphy.

  • As for why this spider would evolve to look like an ant,

  • it's an example of what researchers call

  • defensive or Batesian mimicry.

  • Ants, though small, can be intimidating.

  • Various species can be aggressive or bad-tasting,

  • and can come equipped with biting jaws, venomous stingers, or even sprays of acid.

  • And they can use pheromones to summon more ants.

  • Whereas spiders are predators,

  • but they're not usually well-equipped for defense.

  • They don't have armor plating or thousands of nestmates to call on.

  • There are a lot of animals that might think a spider makes a pretty good snack,

  • like birds, wasps, or even other, bigger species of spider.

  • Which means it might be safer to look like an ant than a spider.

  • These ant-mimicking spiders back up their myrmecomorphy with behavioral mimicry too.

  • They wave their front legs like antennae.

  • They run zig-zag like ants.

  • They even maintain this ruse when hunting.

  • Instead of leaping at prey, they run up and tap it,

  • like a curious, harmless ant would.

  • Then they strike.

  • By doing this, they keep themselves safe from those other spiders and birds,

  • who might prefer not to tangle with the whole biting, stinging, swarming ant business.

  • There are species of katydids and cicada-like insects

  • called planthoppers with similar strategies.

  • But those are still arthropods.

  • Much stranger are the plants that have been hypothesized to mimic ants in a similar way.

  • We know that some plants mimic insects,

  • like the bee orchid that tricks bees into pollinating them.

  • But scientists in Israel have also suggested

  • that dark spots and flecks on plants such as cocklebur and passion flowers

  • might be ant-mimicking defenses against herbivores.

  • But defensive mimicry isn't the only way to pretend to be an ant.

  • An interesting possible case of mimicry comes

  • with some species of spider wasps in Australia.

  • Back in 1969, a scientist in Australia was out looking at a bunch of small,

  • metallic blue ants running about in the sand, when he noticed one was walking oddly.

  • On closer inspection, he also noticed two little nubbinswings.

  • Or the vestigial remains of wings.

  • Which would be unusual on a worker ant.

  • And itswaistdidn't look right either.

  • This wasn't an ant, it was a wasp.

  • Now, wasps already kind of look like ants

  • they're distantly related

  • but the lack of wings and exact color match

  • made it seem like an almost perfect mimic.

  • At first blush, you might call this another example of Batesian mimicry

  • an organism mimicking a more harmful one for defense.

  • But here's the thing: the wasps aren't defenseless

  • They have powerful stingers.

  • So their mimicry isn't a bluff to make them seem more dangerous than they already are.

  • There's another type of mimicry

  • where two harmful species look similar to each other,

  • and both benefit because the overall signal is stronger.

  • It's called Mullerian mimicry.

  • It's like how both wasps and bees carry black-and-yellow warning colors.

  • In this case, the wasp seemed to be sharing Mullerian mimicry with the ant.

  • Either by bite or by sting,

  • predators would learn not to mess with little blue scurrying things.

  • That said, Mullerian mimicry of ants seems to be mostly limited toother ants.

  • Evidence of this beyond a handful of possible examples is a bit sparse.

  • So far we've seen how spiders, insects,

  • and maybe even plants use ant mimicry to keep themselves safe.

  • But some mimics don't just try to pretend to be an ant.

  • They're out to exploit -- and even eat -- the ones they copy.

  • Consider the somewhat uncreatively named large blue butterfly,

  • a species found throughout Europe.

  • Like all butterflies, they start their lives as caterpillars.

  • But these caterpillars spend almost no time eating leaves.

  • Only about two weeks after hatching,

  • the caterpillar goes down to the ground and waits to get found by red ants.

  • The ants, thinking it's a lost ant grub,

  • take it back to the nest, putting it in with the other grubs.

  • There it gets waited on and fed by the nurse ants,

  • mooching off their food.

  • Some species are more aggressive,

  • feeding on the real ant grubs.

  • The caterpillars don't even try to look like ants.

  • Instead, to pull off this con, they use chemical and acoustic mimicry,

  • mimicking the smell of the ants and the sounds of their queens.

  • This is a kind of reproductive mimicry

  • when mimics exploit the host to aid in their reproduction.

  • The most famous example is probably the cuckoo, a bird that lays its eggs in other species'

  • nests.

  • As for what the butterfly gets out of it,

  • ant nests are well-defended,

  • generally free of predators, and have a stable environment.

  • Not a bad place for a squishy little caterpillar to grow up.

  • Over the course of a year or so,

  • the caterpillar will stay in the nest, growing up big and strong at the expense of its hosts,

  • until it pupates and emerges unharmed as an adult.

  • Another example of mimics flying under the radar

  • are the beetles that evolved to look like ant butts.

  • This beetle, called Nymphister, was only described in 2017.

  • They get around the forest floor by latching onto an army ant's butt as they're moving.

  • Curious researchers noticed that an ant they were observing had

  • two butts.

  • This may be an example of tactile mimicry.

  • The beetle feels like the ant.

  • Its size, shape, and shell texture all match the ant,

  • so other workers don't notice.

  • We're not sure how the ant doing the carrying feels about it.

  • And we don't know why they do this,

  • though there are other piggy-back parasites out there that can use the ants as protection

  • or a way to get to new food sources without doing any work.

  • Army ants are fearsome,

  • with colonies that number in the hundreds of thousands of workers

  • They nest only temporarily, going out in group raids to capture prey like other ants,

  • insects, and even small vertebrates.

  • They're just not something you want to mess with.

  • But for those who can, a colony of army ants can be a resource in disguise.

  • Enter the Aleocharinae, a group of rove beetles.

  • They're tricky to find out in the wild.

  • Which could be because you have to go looking for them in swarms of army ants.

  • But they've evolved into superlative ant mimics.

  • Their waists have narrowed, their legs have lengthened,

  • and their antennae have even developed the signature antelbow”.

  • They even smell and act like the army ants,

  • going so far as to lick and groomotherworker ants and even participating in raids.

  • But they're not there for defense.

  • When the beetles get hungry, it's the ants' hard-won food

  • or even their young

  • that the beetles go for.

  • This is known as aggressive mimicry.

  • In aggressive mimicry, the mimic passes itself off as something harmless

  • in order to trick its prey into letting down their guard.

  • This seems to be a successful strategy for rove beetles in particular.

  • One 2017 analysis found it may have evolved at least 12 different times in different species

  • of rove beetle.

  • But not all aggressive mimics have to change their entire bodies to trick their prey.

  • Check out this species of crab spider.

  • Found in Thailand, India, and China,

  • adult spiders prey on weaver ant workers.

  • The spider's strategy is to behave like a dying or struggling worker.

  • Other workers draw near to see what's wrong.

  • Then the spider pounces and runs away with its victim.

  • This is another example of aggressive mimicry.

  • By doing this, the spider can get an easier meal.

  • Finally, remember those jumping spiders that pretended to be ants for defense?

  • One species in particular, the black-footed ant spider,

  • uses its mimicry in an even more interesting way.

  • Because it might have both Batesian,

  • or defensive mimicry, and aggressive mimicry.

  • It lives around Lake Victoria in Africa,

  • and its preferred diet isn't ants or bugs.

  • It's the squishy, nutritious eggs of other jumping spiders.

  • Problem is,

  • it's hard to get to the eggs without running afoul of the adult spiders,

  • who could attack the ant spider.

  • But ants will attack and even eat these other jumping spiders,

  • so the spiders have evolved to be able to watch for, recognize, and run away from ants.

  • And the black-footed ant spider has evolved to take advantage of this behavior.

  • It shows up at its intended spider victim's nest pretending to be an ant.

  • The other spiders, mistaking it for an ant, will run away,

  • letting the ant spider move in and eat the eggs and young

  • before the other spider realizes it's been tricked.

  • So the ant spider has Batesian mimicry

  • the spider's mimicking a scarier animal in order to not get attacked

  • but it's using this trick in order to trick its prey,

  • which would count as aggressive mimicry.

  • It's both a defense and an offense,

  • an incredible example of how nuanced mimicry can be.

  • Life has found ways to use mimicry for virtually every application we can imagine.

  • In fact, ant mimicry alone is estimated to have evolved at least 70 times.

  • In many countries, more than 1 percent of all spiders are ant mimics.

  • If that seems like a lot, well,

  • it's estimated that ants may account for a quarter of the biomass of animals on our

  • planet.

  • So if you're looking for a crowd to blend into,

  • ants are a good option.

  • It's a big crowd to get lost in.

  • Thanks for watching this episode of SciShow,

  • and thanks to one group of people who don't resemble ants at all, except in the sense

  • that they are both numerous, and stronger in a group.

  • Yes, it's our patrons.

  • Thanks for everything you do!

  • If you want to get involved, check out patreon.com/scishow.

  • [ outro ]

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