If you're going to build a robotic spy, you might as well make it a cutie -- especially if it needs to go incognito in crowds of adorable penguin chicks and their parents.

Researchers report in Nature Methods that they've created a new tool for penguin research: A furry fake penguin perched atop a remote-controlled rover.

A fiberglass penguin seemed to frighten the penguins, but the final (fuzzier) version passed muster.

The researchers hope that rover will allow them to really observe and interact with penguins without frightening them off -- or worse, affecting the birds' behavior and tainting the collected data. Other scientists have disguised cameras so penguins won't be afraid to come close to them, but it's another thing entirely to have them interacting with the spy as if it's just another chick.

Instead of running away, the Emperor penguins now sing to the fake chick.

"They were very disappointed when there was no answer," lead author Yvon Le Maho of the University of Strasbourg told Phys.org. "Next time we will have a rover playing songs."

The researchers hope they'll be able to use this fake penguin -- and other, similarly disguised rovers -- to spy on animal populations without putting them on edge.