Various studies conducted from the 1960s to the 1990s found that Racoons have a great memory. They can remember the solutions to tasks for up to three years. Crows can recognize the faces of predatory and benign species and even change their migration patterns when needed for safety. Studies have shown that pigs can understand emotion, show empathy, solve mazes, and even make best friends. Princeton University found that grey squirrels can remember where thousands of nuts are buried for months at a time. African Grey Parrots are as smart as three-year-old children, according to Live Science. This is because they can not only mimic humans but also solve puzzles based on logical reasoning