Cookie, a little penguin (sometimes called a fairy penguin because of its diminutive size) at the Cincinnati Zoo, became an Internet sensation when this video of him being "tickled" went viral. (Skip to the 1:03 mark to hear his "giggle.")

But the truth is that Cookie isn't actually laughing.

“Cookie is not giggling in video, but engaging in typical breeding behavior," zoo spokeswoman Tiffany Barnes told Cincinnati.com. "Some penguins are more vocal than others."

If you're wondering why Cookie is wearing a bandage on his foot, it's because he had a bacterial infection known as bumblefoot.

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