American horned frog Ceratophrys
Frog in a frogDr. Thomas Kleinteich, Kiel University

A CT scan has revealed a frog inside another frog – showing this particular species can catch far larger prey than previously thought.

German scientist Thomas Kleinteich was studying the American horned frog Ceratophrys and had been looking specifically at the sticky characteristics of their tongues.

Previously, he had recorded the forces present when this species sticks its tongue to different surfaces. Findings showed the adhesive forces were significantly higher than the body weight of the animal – it can theoretically lift prey heavier than itself from the ground using its tongue.

"Imagine an 80kg man, who raises more than 110kg in a few milliseconds with his tongue from the floor," Kleinteich said.

American horned frog Ceratophrys
The American horned frog CeratophrysThomas Kleinteich

Researchers believe the mucus on the tongue has a sort of super-glue effect.

To study the animals, Kleinteich, from Kiel University, generates three dimensional computer models using a micro-CT scanner – a machine specially designed to look at small objects.

"We have known for a while that horned frogs are able to eat very large prey. Last year I was able to show experimentally, that horned frogs can produce extremely strong adhesive strength with their tongues, which they also need in order to catch larger prey. With the micro-CT I am able to show, for the first time, how such a large catch can even fit inside a horned frog."