Watch a frog's adhesive tongue in slow motion slap onto unsuspecting prey

Sometimes frogs eat snakes

German researchers from Kiel University have used high speed cameras to record frog tongues in action. One video shows a horned frog flicking out its flypaper-like tongue onto a cricket and then quickly devouring it. Another shows the frog’s tongue latching onto a plate of glass, which was placed in front of a cricket, saving it from the frog’s adhesive tongue...this time.

Science, Space & Robots reports Nov. 2 that the videos were recorded for a research paper published in the Royal Society Open Science journal. The paper is entitled “Frog tongue acts as muscle-powered adhesive tape.” In the paper, scientists Thomas Kleinteich and Stanislav N. Gorb report that frogs’ “high-speed adhesive systems” move so quickly that it’s necessary to view the process in slow motion in order to see just how those tongues do what they do.

Using 2000 frames per second, the researchers were able to capture the “contact mechanics” of the frog’s tongue. The videos allowed them to see that frog tongues roll over the target (the tongue literally slaps down onto an unsuspecting lunch or dinner prospect like a sticky blanket) and then curls back up into the frog's mouth. Once the cricket (or whatever it is the frog is going for) is attached to the adhesive part of the tongue, there doesn’t seem to be any getting away.

“For the first time, to the best of our knowledge, we are able to integrate anatomy and function to explain the processes during adhesion in frog tongues,” write the researchers in their abstract. Essentially, what makes frog tongues adhesive is the way the muscle fibers are arranged on the tongue. They are spread out evenly across the tongue and attach perpendicular to the tongue surface. The way the muscles are arranged over the tongue makes it so that there is an even distribution of force which makes the tongues quick-firing and super-powered. The arrangement of frogs’ papillae (tongue bumps) and a layer of fibrous material under the tongue adapt to many different surfaces. The tongues are also lined with a fair amount of mucus which attach to and can stay attached to prey, even if the prey partially escapes from the tongue’s grip. The equally distributed fibers and mucus allow the frogs to exert a consistent pull until their prey reaches their mouths.

Below follow the two videos from the researcher’s study, along with a few others. Watch as the frogs sit and wait and then slap their adhesive tongues on their prey in a matter of milliseconds (slowed down for viewers, of course).

Royal Society Journal Supplements / YouTube

Watch this horned frog's tongue slap down on its prey in slow-motion

This video was recorded at 1,000 frames per second and is played back at 24 frames per second. Notice how the frog's tongue slaps down on the cricket and then rolls back into its mouth. All of this happens in a matter of milliseconds and is usually difficult to see as clearly as this.

Royal Society Journal Supplements / YouTube

Watch this frog's tongue stick to a plate of glass

This high speed video was recorded at 2,000 frames per second and plays back at 12 frames per second. Notice how the frog's tongue literally sticks to the plate of glass. The way a frog's tongue works has been compared adhesive tape. The quality of frog's tongues has been compared to adhesive.

Stephen Deban / YouTube

Leopard frog tongue projection

This video was filmed at 3,000 frames per second and shows a Leopard Frog, sidelong, projecting its tongue onto its prey. The tongue elongates outwards but is also attached to the tip of the lower jaw.

Jakihro / YouTube

Frogs are sit and wait predators

Frogs are considered sit and wait predators. Watch as this frog patiently waits for the bug to position itself perfectly for the whip of a tongue to catch it before the bug can dodge out of the way.

If it can fit in their mouths, frogs will most likely eat it

Frogs, like these bull frogs, eat just about anything as long as it can fit in their mouths

You may not know this, but frogs aren't just selective eaters. Essentially, if the prey can fit in their mouths, they'll eat it. Fore example, in the case of this bullfrog, that goes for large spiders, snakes, mice, fish, birds, scorpions and even their own kind. Thank goodness frogs aren't any bigger!

*originally published on the now defunct Examiner.com