
kencameron/ Getty Images (game controller); Shutterstock.com (pig)
Not all gamers are human. Last year, researchers trained four pigs to play a simple video game. The pigs learned to use their snouts to move a joystick. If they hit a target on the screen, they got a reward.
These pigs are just one example of brainy animals. Scientists don’t all agree on what proves an animal is smart. Using tools, solving problems, and learning skills are often seen as signs of intelligence. Here are some animals that scientists