New research reveals what makes a frog's tongue

such a formidable weapon.

This is Scientific American. I'm Lydia Chain.

Since the entire attack takes less

than a tenth of a second

the researchers set up high-speed

cameras to capture the action.

"Literally in the blink of an eye, the insect is gone

and it's only when we look at it in

slow-motion can we really see how the

tongue is unfurling from the mouth and

impacting the insect.

That's Alexis Noel at Georgia Tech.

Noel and her colleagues studied frog tongues

and the fluid mechanics of their spit

to understand how frogs slurp up their prey.

First, Noel studied the physical properties of the tongue.

It was so soft, Noel had to design

special equipment to get an accurate

softness measurement.

"It's even softer than brain tissue.

Even softer than a marshmallow."

That soft tongue comes in handy.

Prey sinks deep into the tongue's surface,

increasing contact for a good grip.

The softness also absorbs force

like a bungee cord so the frog can reel in

a cricket rather than giving it a yank

that might cause separation.

But it's the saliva that temporarily

glues the bug to a frog's tongue.

Frog tongues are like spit-saturated sponges

since their salivary glands

are inside the tongue.

Noel and her colleagues analyzed the

fluid properties of this saliva.

"So I scraped about 17 or 18 frog tongues."

Those spit samples revealed frog saliva is

a shear thinning fluid.

The saliva starts out viscous and sticky,

but when force is applied, it liquefies.

The force of hitting the insect

makes the spit splash up around the bug

"And it is able to penetrate all the tiny cracks

and crevices within the insect

increasing its contact area."

After that impact, the spit thickens again,

trapping the insect in the goo.

It's so sticky that the frog needs to

shove its eyeballs onto its tongue

in order to loosen the spit enough to swallow its morsel.

It's that combination of the soft tongue

and the sticky saliva

that lets frogs scoop up prey in an instant.

Of course not even super spit can help the frog

if it bites off more than it can chew.

For Scientific American, I'm Lydia Chain.