[ ♪Intro♪ ]
  Whether they're pets, wildlife, or the residents  of the local zoo, animals can sometimes seem
  a lot like us.
  Usually, if you think your cat looks guilty,  you're just being anthropomorphic -- or
  finding human traits in nonhuman things.
  Because let's be honest: Your cat probably  doesn't feel guilty about anything.
  Still, some animals do have behaviors that  seem oddly similar to the things we do.
  Their motives normally aren't the same,  and the behavior often isn't as complex,
  but it can make some of the stuff we humans  do seem almost universal.
  Here are six of the weirdest.
  If you've ever been cut off by a bad driver,  you know humans are great at holding grudges.
  But we're not the only ones.
  Crows are known for being really smart, and  an experiment done in Seattle in 2011 showed
  that they'll also hold grudges… for years.
  At five different sites, researchers put on  a distinct mask, captured between seven and
  fifteen crows, and attached identifying bands  to their legs.
  And after they were released, those crows  remembered the "face", or mask, of their
  persecutor for a long time.
  Anyone assigned to walk around in the mask  would be subjected to loud crow scolding -- or
  angry cawing -- and even dive-bombing.
  Talk about drawing the short straw.
  But according to the paper, which was published  in the journal Proceedings of the Royal Society
  B, it wasn't just the captured crows that  were angry.
  Other local crows that hadn't been captured,  as well as young crows born in the following
  years, picked up this behavior as well, apparently  learning from their flockmates or parents
  that the mask was dangerous.
  The scolding behavior spread over a kilometer  from the original capture sites and persisted
  for at least five years.
  A follow-up study using PET scans, published  a year later in Proceedings of the National
  Academy of Sciences, showed that when captured  crows saw the threatening mask, the same parts
  of their brains were activated that light  up in human's brains in response to fear-based learning.
  Still, a grudge like this probably isn't  the same as the ones we keep.
  Because, honestly, we're usually a lot pettier  and not in actual danger.
  In crows, this behavior shows that they can  alert each other to threats in their environment,
  which is important for avoiding predators  and raising their young.
  Still, if you're planning to visit Seattle,  maybe avoid wearing a mask.
  We warned you.
  All kinds of studies have shown that humans  don't do well in isolation.
  Loneliness increases our risk for all sorts  of things, including infections and depression.
  And, as it turns out, cows are better when  they have friends, too.
  On a typical dairy farm, calves are separated  from their mothers shortly after they're
  born, then are housed alone for eight to ten  weeks while they're weaned.
  This is supposed to slow down the spread of  disease between individual cattle, which can
  be a problem when you've got a lot of animals  sharing limited space.
  But scientists also noticed that cows raised  alone tend to be more awkward and anxious
  when they joined a herd.
  So they came up with two experiments to compare  calves housed alone with those raised in pairs,
  and their results were published in 2014 in  PLOS ONE.
  In the first experiment, eighteen baby cows  were confronted with a Y-shaped maze with
  a white box in one arm and a black box in  the other.
  The scientists taught the calves to expect  full bottles of milk in only one color box,
  then switched it around to see how long it  would take for them to catch on.
  And the calves that were raised with a buddy  were quicker to figure it out than the loners.
  In the second experiment, researchers showed  those calves a red plastic bin eight times
  over a couple of days, letting them interact  with it for up to five minutes.
  The calves raised in pairs got bored with  it pretty quickly, and spent less time interacting
  with it each time -- because, well, it's  just a bin.
  But the calves that were raised alone kept  coming back to check it out again and again.
  Put these two tests together, and they suggest  that the calves raised in pairs were more
  flexible and probably less anxious, able to  adjust to changes in their environment faster.
  In other words, cows need friends, too.
  Meanwhile, African wild dogs have lots of  friends.
  They're among the world's most social  canine species, and they live in packs led
  by a dominant breeding pair.
  Before the pack heads out on a group hunt,  they need to reach an agreement about their
  course of action.
  To do this, they take a vote… by sneezing.
  Thankfully for our immune systems, we humans  have ballots.
  Scientists discovered this behavior by observing  rallies, or big group interactions the dogs
  have before a hunt.
  They followed five different packs -- about  50 total dogs -- for almost a year, and published
  their results in Proceedings of the Royal  Society B in September.
  They noticed that during rallies, individual  dogs make noises that sound a lot like a sneeze
  -- although they're not actual sneezes,  just a fast, exhale through their nose, like a huff.
  After analyzing almost 70 recordings of these  pre-hunt rallies, scientists found that the
  more sneezing was going on, the more likely  it was that the pack would hunt.
  In other words, it seemed like the sneezing  was a kind of voting mechanism.
  Now, voting isn't actually unique to African  wild dogs -- other social species, including
  meerkats and capuchin monkeys, have their  own ways of reaching agreements.
  But remember how each pack is ruled by a couple  of dominant dogs?
  If the pre-hunt rally was initiated by one  of these power players, it took about 10 fewer
  sneezes on average for the pack to come to  agreement and move out -- even though the
  dominant dog could still be overruled with  enough votes.
  Just like in human elections, some individuals  ultimately have more sway than others.
  But when African wild dogs start running campaigns,  we'll let you know.
  If you get a bunch of people together, there's  a good chance someone will start gossiping.
  And, based on research, we think dolphins  do, too.
  Individual bottlenose dolphins have identifying  whistles that act a lot like names.
  They'll respond to recordings of their own  so-called "signature whistles," and they
  use them to call out to each other when restrained.
  Except, unlike humans, dolphins don't assign  these whistles to their babies when they're born.
  Dolphins develop their own when they're  a few months old, and they can also be used
  to convey their mood, not just their identity.
  They don't often use the whistles within  their own groups, but they do exchange them
  when meeting other groups -- like a proper  introduction.
  But sometimes, the signature whistles they're  using aren't their own: They're whistles
  that refer to other dolphins that aren't  around.
  Scientists are still figuring out why, but  it seems that they're talking about these
  individuals behind their backs -- or behind  their dorsal fins.
  But because we don't totally understand  how they work, it's probably not identical
  to human gossiping.
  Instead, they might just be trying to figure  out where their missing buddies are.
  Still, all that complex social behavior may  have started the same way it did in humans:
  with large brains.
  A study published in Nature Ecology & Evolution  in October looked at behaviors in 90 species
  of whale and dolphin, and found that those  with larger brains have more complex social lives.
  This fits with something called the cultural  brain hypothesis -- the idea that our big
  brains evolved to help us deal with living  in social groups.
  And now, that may apply to dolphins as well.
  So, gossipping may actually be a sign of advanced  intelligence… but don't tell your busybody neighbor.
  If you've ever been told you see the glass  half empty, you can probably relate to honeybees.
  Research published in the journal Current  Biology in 2011 showed that when things get
  stressful, bees become pessimists -- like  you on a Monday.
  To test this, scientists trained bees to associate  different mixtures of two smelly chemicals,
  hexanol and octanone -- which are carbon chains  with an atom of oxygen -- with different foods.
  Mixture one was mostly hexanol with a little  bit of octanone, and was paired with delicious,
  sugary foods.
  Mixture two, which was paired with bitter-tasting  quinine, had the ratio flipped, with more
  octanone than hexanol.
  The bees quickly picked up on this and rejected  the bitter food that smelled like the second mixture.
  Then, to change the bees' mood, the scientists,  well, shook it up a bit.
  They took half of the bees and gave them a  hard shake on a vortexer, a machine used to
  mix chemicals, which simulated a predator  attacking their hive.
  Afterwards, those stressed-out bees had noticeably  different reactions to the food.
  Both groups were eager to check out the snack  that smelled more like hexanol, since they'd
  been trained to associate it with sugar.
  But the shaken bees were more hesitant overall.
  The biggest difference was when the bees were  given food scented with a fifty-fifty mixture
  of the chemicals -- a mix that could have  been delicious or bitter.
  The stress-free, unshaken bees went for it  like optimists.
  But the shaken bees seemed more pessimistic  and stayed back, since there was a chance
  it would be disgusting.
  Scientists think the stress could have affected  the bees' brain circuits that encode their
  memories of smell, based on the drop they  saw in certain neurotransmitters.
  Similar tests on humans, monkeys, dogs, and  birds show that we all become more pessimistic
  after a stressful experience.
  And it's especially cool that this also  happens in invertebrates, like bees.
  Still, since bees lack an equivalent of many  of our basic brain structures, we can't
  really know if this means they experience  emotions in a way we'd find familiar.
  But scientists think it's a possibility  worth considering.
  And finally, penguins…
  They aren't as innocent as you think.
  Adélie Penguins build their nests out of  hundreds of stones, creating a platform that
  can keep their eggs safe from floodwater in  the spring.
  They treat these rocks as valuable objects,  fighting over them and stealing them from
  each other's nests -- but sometimes, they'll  go even further than that.
  These penguins are socially monogamous, meaning  they pair off with one partner to raise their
  young… but they're not necessarily sexually  monogamous.
  Paired-off female penguins will often head  out to collect stones to build their nests.
  And according to research from the journal  The Auk in 1998, these wandering ladies have
  been observed soliciting sex from single males  in exchange for rocks.
  These females aren't changing their mind  about their mate, either -- they're just
  offering a one-time hook-up for stones.
  In other words, they're doing something  that looks remarkably like prostitution.
  Occasionally, these females even initiate  a courtship ritual... but then leave with
  a stone without actually copulating.
  One female penguin just kept doing this and,  by going back and forth, gathered at least
  62 stones from a single male in an hour.
  Now, according to the study's author, only  a few percent of female Adélie Penguins actually do this.
  And even though the rocks are a useful prize,  there may be more going on, too.
  It takes hundreds of rocks to build a nest,  and the lady penguins usually only get one
  or two from the single males.
  So there's also a chance they're looking  for potential mates in case theirs dies, or
  are trying to make sure their offspring are  extra healthy.
  Either way, this is the only animal species  we've seen where individuals trade sex for
  anything other than food.
  And all those cute penguins in documentaries…  are maybe not as child-friendly as they seem.
  Whether it's lonely cows or busybody dolphins,  many animals have lives that seem a lot like
  ours -- even if most human behaviors are still  more complex, or happen for different reasons.
  But the next time you're feeling pessimistic  or having a hard time with a grudge, at least
  you'll know you're not alone.
  Thanks for watching this episode of SciShow!
  If you'd like to learn even more weird animal  facts -- or stories about a bunch of other
  weird stuff -- you can go to youtube.com/scishow  and subscribe.
  [ ♪Outro♪ ]
     
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