Is it a bird? Or is it a bunny?

That's the question sparked by a video that's gone viral. The clip shows a bird, with its beak in the air, and a human stroking its head. But looked at from a different angle, the beak appears similar to bunny ears.

Dan Quintana, a senior researcher in biological psychiatry at the University of Oslo in Norway, posted the video to Twitter Sunday, alongside the caption: "Rabbits love getting stroked on their nose."

YANNY OR LAUREL? INTERNET SPLIT ON WHAT NAME THEY HEAR IN AUDIO CLIP

He told CNET he "thought it was fairly clear that the video was of a bird... as you can see the translucent nictitating membrane sweep across the eye horizontally (rabbits don't have membranes like this) and the positioning of the 'ears' are a little strange."

"I made the rabbit comment to prime readers into thinking it was actually a rabbit, to give it a fighting chance at least," Quintana said. "When you only see the beak in your peripheral vision, it really seems like they're ears. Without this misleading cue, I thought most people would have seen a bird."

CLICK HERE TO GET THE FOX NEWS APP

The optical illusion reminded some of similar debates: "The Dress," in which some people saw a black and blue dress that others saw as gold and white, and "Yanny or Laurel," in which some people heard a computerized voice saying different names.

"Here's my rabbit," one Twitter user joked, posting a video of a large snail, while another user said the video showed "Clearly a bird. The 'ears' are hard and unmoving. Also in the wrong place."

"Seriously what am I looking at? I can't handle this kind of mental pressure right now," someone tweeted.

Quintana said, "About two-thirds of people are insisting it's a bird, and the remainder are either insisting it's a rabbit or can't decide."