We usually think babies are adorable, but dragonflies turn that belief on its head, thanks to the way their heads are built. A dragonfly nymph's jaws — or lower lips, really — inspire visions of terrifying science fiction monsters.

KQED Science took an up-close look at these little guys, exploring just how dragonflies and damselflies survive as larva. They have an adaptation for eating that is unlike anything you've probably seen.

"It’s like a long, hinged arm that they keep folded under their head and it’s eerily similar to the snapping tongue-like protuberance the monster shoots out in the 'Alien' sci-fi movies," notes Gabriela Quirós of KQED Science. "A nymph’s eyesight is almost as precise as an adult dragonfly’s and when they spot something they want to eat, they extrude this mouthpart, called a labium, to engulf, grab, or impale their next meal and draw it back to their mouth. Only dragonfly and damselfly nymphs have this special mouthpart."

Here's an image of the labium mid-attack:

The jaw of a baby dragonfly looks like something out of a sci-fi horror movie. The jaw of this common green Darner dragonfly nymph extends to snag prey, then retracts to bring it in for a meal. (Photo: KQED Science)

Creepy and yet undeniably fascinating, this adaptation has taken some 320 million years to perfect. In the underwater world in which the nymphs live for months or even years before transforming into adult dragonflies, this adaptations provides a way to gather food and eat it, all with one tool.

Want to see this "killer lip" in action? KQED's Deep Look video takes you under water and shows you just how this specialized tool is used.

Jaymi Heimbuch ( @jaymiheimbuch ) focuses on wildlife conservation and animal news from her home base in San Francisco.

A dragonfly nymph's mouth is the stuff of nightmares
This video shows how the unusual jaw structure of dragonfly and damselfly nymphs is both brilliant and terrifying.