Nature is full of interesting and unique creatures that vary in shapes, sizes and function. The fun part for researchers is figuring out how each creature functions.

When entomologist Aaron Pomerantz yelled down to his team from the top of a canopy tower in the Peruvian Amazon, a quick little movement caught his eye. He took a closer look.

Screen Shot: YouTube/
Rainforest Expeditions

What he saw was a bizarre-looking caterpillar with four appendages protruding from its back. The tentacle-esque extremities were apparently sound-sensitive -- when Pomerantz yelled to his group, they extended out in different directions, then once again retracted. They speculated that the behavior must be a defense mechanism to distract predators or to blend in with flora.

Screen Shot: YouTube/
Rainforest Expeditions

Pomerantz and his team took turns filming and yelling at the insect to document its strange behavior. None of them had seen anything like it before. They thought it was a brand new species.

Screen Shot: YouTube/
Rainforest Expeditions

Back in the U.S., after some research, Pomerantz found that this behavior in fact had been documented before, in a caterpillar called the horned spanworm. Now he thinks the caterpillar he found might be that species, although it's difficult to tell at the larval stage. Here's a video of the horned spanworm:

[media height="270" width="480" provider="youtube" type="iframe" src="https://www.youtube.com/embed/RoxA1Xy7k5k?feature=oembed" ad="true"]

Be sure to share this with all your curious bug-loving friends.