We think we know what water feels like, how it behaves.

But perception is a matter of scale.

For very small animals – water feels different.

It has different properties.

It’s almost gooey.

And for some insects, this strange fact is key to their survival.

Meet nature’s scuba divers.

They can breathe underwater.

Because they carry their air with them— in some cases, for a lifetime.

What makes this possible is a force almost too subtle for bigger animals, like us, to notice: surface tension.

Here’s how it works… Water molecules are drawn to each other.. they’re kind of sticky.

At the surface, that creates a ... film... that can actually carry weight.

That’s surface tension.

It also allows bubbles to form.

This beetle traps a bubble with his outer wings.

He hauls it under the surface while he hunts for food.

See how the bubble is attached to his rump?

That’s where his breathing holes are.

They’re called spiracles.

When he’s used up the oxygen in the bubble, he lets it go.

And returns to the surface for a new one.

These beetles have a different technique.

They’re born on land but enter the water as adults.

And they never go back.

That’s because part of their shells are covered in tiny bristles, which use surface tension to trap a layer of air known as a plastron.

That coating of air gives this beetle a gold shimmer, almost like she’s in a space suit.

Surface tension keeps a whole underwater menagerie alive.

All these insects have found ways to carry air with them underwater.

But it’s fragile.

Just a little bit of soap can disrupt surface tension - destroy its magical properties.

When surface tension breaks, a whole world can drown.

Just like these paper clips sinking to the bottom of the bowl.

And even though we’re bigger?

We still rely on it.

Surface tension allows raindrops to form, trees to carry water to their leaves, ice to float.

We may not always notice surface tension.

But we need it, just as much as they do.