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Somewhere near you,
an animal is defecating.
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In fact, each day, the animal kingdom
produces roughly enough dung
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to match the volume of water pouring
over the Victoria Falls.
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So why isn’t the planet covered
in the stuff?
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You can thank the humble dung beetle
for eating up the excess.
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Capable of burying 250 times
their body weight in a single night,
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these valiant insects make
quick work of an endless stream of feces.
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Over 7,000 known species of dung beetle
run clean-up duty across six continents
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—everywhere except Antarctica.
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A dung beetle’s first task
is to locate dung.
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Some live on the anal regions
of larger animals,
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ready to leap off when they defecate.
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Others sniff out feces
that animals leave behind.
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A pile of elephant dung can attract
4,000 beetles in 15 minutes.
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So once a beetle finds dung,
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it must work quickly to secure
some of the bounty for itself.
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Most dung beetle species fall into one
of three main groups:
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rollers,
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tunellers,
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and dwellers.
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Dung rollers sculpt a ball of dung,
and using their back legs,
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quickly roll it away from competitors.
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Potential partners jump on the ball,
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and once the ball-maker
has selected their mate,
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the pair dig their dung ball
into the soil.
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Once it’s been buried, the female lays
a single egg within the dung ball.
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Tunnelers have a different approach.
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Digging underneath a pat,
some drag dung down into the soil
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and pack it into clumps
known as brood balls,
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dung balls,
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or dung “sausages,”
depending on their shape and size.
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Male tunnelers sport a spectacular
array of horns
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to fight each other
for control of these tunnels,
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which they then defend
until the female’s laid her egg.
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Some male tunnelers avoid the fray
by masquerading as hornless females
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and sneaking into tunnels to mate
while the guardians’ heads are turned.
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The third group of dung beetles, dwellers,
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take the most straightforward approach,
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laying their eggs
directly into a dung pat.
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This makes their offspring
more vulnerable to predation
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than those of the tunnelers and rollers.
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As the larvae feed, they riddle
the dung pat with tunnels,
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leaving remains that are quickly colonized
by bacteria and fungi and weathered away.
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Inside a tunnel, ball, or pat,
once the larvae hatch,
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they consume the dung
before metamorphosing into a pupa
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and then an adult beetle.
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Besides clearing dung,
the actions of these beetles
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have considerable ecological importance.
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For one, they serve as secondary
seed dispersers.
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Dung from monkeys,
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wild pigs,
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and other animals is riddled with seeds
from the fruits they eat.
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When beetles bury their dung balls,
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they inadvertently protect these seeds
from predators
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and increase the likelihood
they’ll germinate.
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The advantage is so great
that one South African plant
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has evolved to produce seeds that look
and smell like dung
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to trick beetles into burying them.
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Dung beetles also play important roles
in agricultural systems.
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Livestock, like cows and sheep,
produce huge amounts of dung,
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which contains nutrients
that can benefit plants.
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The beetles break up the dung
and tunnel it deep into the soil,
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bringing the nutrients into close contact
with plant roots.
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Their services to farmers have been valued
at $380 million a year in the US
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and £367 million a year in the UK.
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Dung beetles can even help us battle
global warming
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by reducing greenhouse gas emissions
associated with farming.
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Microbes living in oxygen-poor
livestock dung
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produce methane, a potent greenhouse gas.
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But beetles oxygenate pats when
they tunnel into them,
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preventing the microbes
from producing methane.
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The dung beetle spreads seeds,
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helps farmers,
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and fights climate change
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—and accomplishes it all
simply by doing its business.
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Maybe next time you come across
some dung in the forest or a field,
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you’ll be tempted to take a closer look.