Bird or bunny? The latest optical illusion is freaking people out

This video of an animal having its head stroked may have you scratching your own.

Is it a bird or a bunny?

It's a burning question that has taken its place in the pantheon of internet-dividing debates, like the color of #TheDress in 2015 or whether a voice was saying Yanny or Laurel in a viral audio clip last year.

Rabbits love getting stroked on their nose

— Dan Quintana 🐰 (@dsquintana)
Daniel Quintana, a biological psychiatry researcher at the University of Oslo in Norway, started the debate with a tweet that showed an animal being rubbed on the head.

"Rabbits love getting stroked on their nose,'' he wrote.

But is it a rabbit? Or is that a bird having the back of its head stroked?

Wow, I sat here for ages seeing someone petting a crow w its beak open to the air, and thinking “rabbits??”

— Dr. Nic Thompson (@NicoleAlineSci)

I see a raven. Anyone else?

— TravellingMan (@SJJB55)

It looks like you are stroking the head of a crow. Wild.

— The Electric Agora (@ElectricAgora)
The video was originally posted on Aug. 17 by Imgur before Quintana decided to have a little fun with it a day later.

And the correct answer is...

"I thought it was fairly clear that the video was of a bird,'' he told CNET. "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."

#TheDress is black and blue - or white and gold?

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Of course! Who didn't see the *checks notes* nictitating membrane across the eye? It's clear as day!

Oh wait, somebody actually did.

That is not a rabbit, it is indeed a Corvid. Notice the nictitating membrane when it blinks. Instead of moving up and down, it sweeps across the eye horizontally like a windscreen wiper and is translucent.— Greta GG (@GretaGarbolini)
Corvids are a bird family that includes ravens and crows, which some other eagle-eyed folks guessed in the comments.

Some pointed out the video was a real-life version of a popular drawing of a duck-rabbit illusion from the 1800s that went viral in 2016.

The optical illusion came to life, it's official, someone has a magic pen!!!

— Keisha Renee (@Broadwaybandit5)

The odd position of the bunny "ears" — actually the bird's beak — appeared to be the real giveaway.

"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,'' Quintana said.

Now that the mystery is solved, the bird-bunny video can join the proud history of optical illusions involving hugs , tile floors and more that made everyone on the internet take a few moments together to wonder what we're staring at.

Parrots, according to the Humane Society of the United States (HSUS), are the nation’s fourth most popular pet; according to a 2012 survey conducted by the American Veterinary Medical Association (AVMA), 3.1 percent of U.S. households owned birds. Some parrots can scream as loud as an ambulance siren. These birds are beautiful, but they’re difficult to care for and require lots of space, so the HSUS doesn’t recommend keeping them as pets at all.