How do some amphibians and reptiles catch bugs with projectile tongues?

Imagine if your tongue was 80 per cent the length of your body and you could poke it out and reel it back in within 20 thousandths of a second. Well, if you’re a lungless Hydromantes salamander that’s one ability you already possess.
Creatures like frogs, chameleons and salamanders have a staple diet consisting mainly of insects. In order to make a quick getaway, most of these bugs have evolved sensors that detect even the slightest movements made by their would-be assassins, so the hunter must be able to get close without being detected. To help them grab a bite, some amphibians and reptiles have very long and sticky tongues – perfect for catching flighty prey without having to get so close. While most of these animals strike out using elastic recoil, Hydromantes do things a little differently…

The Hydromantes salamander is the proud owner of the fastest tongue on Earth. This appendage is not only the longest amphibious tongue, but it’s also one of the most accurate tongue-protrusion mechanisms seen in nature. To ensure it doesn’t go hungry it uses a built-in ballistic projectile to grab its next meal. Imagine the tongue as a tethered arrow being
fired from a bow.

The tongue consists of a bony skeleton surrounded by protractor muscles that store elastic energy. While the tongue skeletons of other amphibians are found in the base of the mouth, in this lungless species of salamander the resting tongue skeleton extends over the shoulders.

The tongue snaps back into the mouth with the help of long retractor muscles connected to the pelvis. The retractor muscles don’t have the same power as the protractor muscles, but the tongue still recoils back into the mouth very quickly.