Tip of the Tongue

(Excerpted from Nature's Predators, published by KidHaven Press and available online in Kids InfoBits )

A frog's tongue is a deadly weapon. In less time than it takes to blink, a frog unrolls its tongue, shoots it out to snag nearby prey, then rolls it back inside its mouth. This movement is so fast, it can hardly be seen by the human eye. Scientists have been able to study the actions of a frog's tongue only through the use of special cameras and high-speed photography.

The frog's tongue is attached to the front of its mouth and folds back inside. When a frog attacks, the tongue comes forward like a human arm does when flipping a yo-yo. The part of the tongue that strikes the prey is similar to the back of the hand, not the palm.

Once the prey has been hit, the frog folds its tongue back into its mouth. It is the tongue's pliability that makes it seem to roll back in like a party favor.

A few species of frogs do not use their tongues to capture food. Instead of a sticky tongue, they have strong arms and legs. Aquatic frogs and clawed frogs have no tongues. Such frogs sit motionless in the water, with their arms and hands stretched wide, waiting to feel motion in the water.

Fire-bellied toads have short tongues that cannot be extended beyond their mouths. The toad uses its hands to scoop the prey toward its mouth, while lunging forward so the prey can be pushed inside the body.

The African clawed frog has no tongue. It stuffs a meal in its mouth, then clamps its jaws closed to keep any prey from slipping loose. This can be difficult since these frogs prefer larger prey, such as mice or other frogs.