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  • To us, water striders are almost magical.

  • I mean, come on, they're literally walking on water.

  • But come down to their level and it's a bit moresinister.

  • These delicate little bugs have figured out how to master the elements -

  • and to exploit those who can't.

  • So how do water striders float where others sink?

  • The answer is those crazy long legs.

  • Water is pretty sticky stuff.

  • It likes to hold onto itself.

  • It sticks together especially well right at the surface.

  • If you're small, it can actually hold you up, as long as you don't break through that

  • surface tension.

  • It seems like the water strider's legs would just sink right in.

  • But they don't.

  • They make dimples on the surface.

  • That's because their legs are covered in tiny hairs called micro-setae that repel water.

  • The strider's entire body is covered in them.

  • Those hairs trap a layer of air that keeps the water from sticking to its body.

  • The water strider simply can't get wet.

  • That's how they can sit on top of the water without breaking through.

  • Plus they're pretty light and they spread out their weight with their front and back

  • legs.

  • They use their middle pair of legs to maneuver, by pressing down and back against those dimples.

  • Just like rowing a boat.

  • They can even catch some air.

  • Most of their fellow insects aren't quite as graceful.

  • Like this caddisfly.

  • Struggle as it may, it's stuck.. half-drowned

  • Exactly what the water strider has been waiting for.

  • It probes for a weak spot

  • And pierces through - spitting digestive enzymes in that dissolve its victim from the inside.

  • Then the striders take their time sucking out the innards.

  • Leaving the caddisfly a dried-out husk.

  • The stream delivers an endless buffet of new victims.

  • Because for most, that razor-thin line between water and air is a treacherous place.

  • But water striders know:

  • keep your feet dry and you'll always have the upper hand.

  • Hey there, it's Lauren.

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  • Keep up with all the weird, gross and wonderful things we're working on.

  • Thanks and see you soon.

To us, water striders are almost magical.

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這就是為什麼水黽會成為可怕的救生員|深究 (This Is Why Water Striders Make Terrible Lifeguards | Deep Look)

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    brian98059 發佈於 2021 年 01 月 14 日
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