The test subject sat looking inquisitively at the screen. After giving it a little thought, he pecked out groups of shapes in proper numerical order, starting with one rectangle, then selecting the group of two rectangles, then three, on up. The onlookers seemed delighted at the evidence that their subject could count.
That subject wasn't a toddler learning his numbers, nor was it a pet. The counting creature was an animal that's likely way smarter than your pet: a pigeon. (Of course, if you have a pet pigeon, you're not surprised at all.) The pigeon's just one example of an animal some humans eat that's probably smarter than your pet kitty or guinea pig.
If that's the case, maybe you're thinking we shouldn't be eating animals from this list because it's a waste of their brains. Well, when you see that the pig made the top 5 and you start thinking about bacon, you may change your mind.
Pulled pork, pork chops, bacon ... the list of pig-based foods that we eat goes on and on, but for some reason, we never really talk about pig brains. Why think about pig brains when we can be thinking about eating a ham sandwich? Turns out that pigs also have food on the mind, and they've shown how intelligent they can be when it comes to getting more of it.
For example, domestic pigs can learn quickly how to put mirrors to use, peering at the reflected images of their environment to find food. Scientists also have done tests showing that pigs can instantly learn to follow each other when they think another pig knows the location of food. Even better, the leading pig often will try to throw the follower pig off the trail, so that it won't have to share the food [source: Angier].
It's not just the hunt for food where pigs show off their smarts. Pigs can be trained to do all sorts of tricks – jump through hoops, close and open cages, play video games with joysticks and even herd groups of another very smart animal we eat as food – sheep.
We usually think about eating the baby form of sheep, lamb, but people consume adult sheep as well, mostly in France, Africa, the Caribbean, the Middle East, India, parts of China, Australia, and New Zealand [source: Apple]. We just call it mutton when it shows up on our dinner plate.
The tendency of sheep to follow their flock can leave people with the impression that these animals aren't the sharpest tools in the shed. Enter science to prove otherwise! Scientists have shown that sheep are at least as smart as rodents, monkeys, and in some tests, even humans. They recognize people, respond when you call their names and can react to the nuances of different facial expressions. Even cooler, these animals can form a mental map of their surroundings, and they show signs of being able to plan [source: Gray].
Taken individually, sheep show off their smarts much more so than when they're together in a flock. It's just rare that we encounter them alone, so we don't often get the chance to see them shine.
And now from the turf to the surf! Animals that might outsmart your pet aren't just found on land. Thought to be the world's smartest invertebrate, the octopus is a part of meals in countries across the Mediterranean and Asia, and is growing in popularity outside those regions as well [source: Bittman].
As tasty as this animal may be grilled with a squeeze of lemon, instead of eating it, we should be admiring it for its brain. The octopus brain is very complex, sharing features such as folded lobes and similar brainwave patterns with mammalian brains [source: Schweid]. Tales of octopuses opening jars, breaking out of cages and solving somewhat complex spatial problems abound. They take things apart, navigate their way through mazes and play. While that last point may sound silly, play actually demonstrates intelligence, showing just how well an animal can figure out and interact with its environment [source: Schweid].
A close cousin to the octopus with a very high brain-to-body-size ratio, the squid also swims onto this list. We're used to eating this cephalopod as calamari – fried, grilled or maybe folded into a seafood stew. As with an octopus (but not a human), the squid's brain is quite decentralized. In fact, three-fifths of it resides in the arms and tentacles, making individual tentacles able to act on their own [source: Williams]. However, the squid's brain is made of the same types of brain cells we have – neurons. Thanks to this shared cellular anatomy, we're actually able to learn a lot about ourselves by studying squid.
Squid are more difficult than octopuses to keep in the laboratory, but scientists have found that they too are good problem solvers, especially when it comes to escaping predators. And like humans, newborn squid use their brains to learn through a process of trial and error [source: Schwartz]. Perhaps the smartest part of a squid that scientists know the most about? Their skin. With thousands of color-changing cells called chromatophores just below the surface of their skin, squid can change color to blend into their backgrounds in the blink of an eye.
For the final animal on our list, we come back to the pigeon, better known on your dinner plate as squab. So maybe they aren't quite doing calculus, but these birdbrains actually are quite talented at math. The street pests can learn abstract rules about numbers, demonstrating an ability to count off shapes, rank them in ascending order, and perceive differences in numbers of groups of objects [source: Gorman].
Beyond math, pigeons have shown that they're able to recognize people who've been hostile toward them in the past and avoid them in the future [source: Gibson]. They can also recognize themselves in prerecorded videos [source: Toda and Watanabe]. Lastly, while you think these birds may be uncultured annoyances, they may be able to one-up you in museums, discriminating between Monet and Picasso paintings [source: Watanabe et al.]. Not bad for a bird you may order up to eat in a restaurant.
We look at how people use the bands of color on a woolly bear caterpillar to determine how harsh a winter will be – and whether it has any merit.
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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