Why are frog and toad tongues so fast and sticky?

“Toads nab their prey 5 times faster than the blink of an eye. How do they do it? They pop their lower jaw open, and launch their supersoft tongue at their meal, enveloping their prey. When their unique saliva hits prey at a high speed, it thins out dramatically, pouring into every nook and cranny the tongue touches. Then it becomes sticky again, drawing that meal down the hatch.”

So what’s going on with the flexible tongues and versatile spit of frogs? When researchers at Georgia Tech took a closer look, they found that frog tongues are “as soft as brain tissue and 10 times softer than a human’s tongue,” stretching and storing energy “much like a spring.”

Combined with non-Newtonian spit that changes its viscosity from that of water to honey, then back to water again in less than a tenth of a second, crickets and other meals have little chance for escape.

Next, take a look at x-ray footage of a cane toads’ tongue, filmed by University of Florida researchers. They found that toads swallow their tongues, scraping off prey on the cartilaginous hyoid, the tongue’s supporting frame­work.

All of this is summarized in this Deep Look episode from KQED: Toad Tongues Slay With Seriously Sticky Spit.

Alexis Noel, a mechanical engineering Ph.D. student, discusses the research in this 2017 Georgia Tech video:

Could a better understanding of frog and toad tongues and non-Newtonian saliva help scientists create stronger or more sustainable reversible adhesives?

Watch these related videos next on TKSST:
• Why is ketchup so hard to pour?
• The science of oobleck
• A tiny desert rain frog hunts for termites at night
• Toad Feeding Session: Do these toads want to share their lunch?
• African bullfrogs battle for the center of the pond