Name: Sticky. Stretchy. Waterproof. The Amazing Underwater Tape of the Caddisfly | Deep Look
Uploaded: 2019-11-05T08:03:13.000Z
Duration: 3 min 51 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

To us, it's a tranquil mountain stream…

But if you're a bug living on those algae-covered rocks in the water?

All you need are some raw materials...and a little tape.

This insect has evolved a tool that's eluded us humans so far: tape that stays sticky underwater.

As winged adults, caddisflies are a favorite food for trout.

Artificial lures mimic them in painstaking detail.

But they spend most of their lives as larvae in shallow, turbulent water, which is rich

And though its head and legs are covered in a thick layer of insect armor, or chitin...

...its soft, white lower body is more exposed.

To the elements, and especially to any passing predators.

So the caddisfly has figured out how to build a case...for ballast, protection,

It does this by binding together pebbles with a special silk that looks, and acts, a lot

It's like...the cornerstone of a building.

The caddisfly adds more pebbles, one by one, like a bricklayer putting up a wall, using

When he brushes the surface with his mouth, that's his tape dispenser working.

These flies are VERY particular about their building stones.

When he finds a match, he fits it into place.

Once he tapes down the basic shape of the case, he seals it up from the inside, in a

The problem with our tape is that when it's wet, it loses its stick.

What's more, the ribbon itself is like a rubber band.

It can stretch to twice its size and return to the same shape.

It's a rubber band that moves like molasses.

That's a lot safer for the vulnerable larva living inside.

Bio-engineers have started to figure out how we could make our own caddisfly silk.

Maybe as as a kind of internal surgeon's tape.

To replace the metal and string that we use to patch people up now.

The magical underwater tape of the caddisfly.

Another example of how evolution finds radical solutions to everyday problems.

That's what we do at Deep Look: zoom way way in to very small worlds.

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Sticky. Stretchy. Waterproof. The Amazing Underwater Tape of the Caddisfly | Deep Look

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