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HowStuffWorks takes a look at gastroliths, or 'stomach stones' and why some animals eat them.
Author's Note: 5 Food Animals That Are Smarter Than Your Pet
I'd heard that pigeons were smart before, but it wasn't until I delved into researching this article that I truly got a good grasp of their intelligence. I'm not generally an animal hater – quite the opposite, actually. But pigeons are in another category altogether. Let's just say I'm not fond of them, to put it mildly. But now that I know how smart they are, I kind of feel like I should tip my hat to them. The birds are practically born with degrees in math and art history. Seriously?!?
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