8 Raccoons : Raccoons are especially cunning animals, and may even be more cunning the fox. In a study by the ethologist H. B. Davis in 1908, raccoons were able to open 11 of 13 complex locks in fewer than 10 tries, and had no problems repeating the action when the locks were rearranged or even flipped upside down. Multiple studies conducted throughout the 20th century have shown that raccoons have an extraordinary memory, and can remember the solutions to problems for up to three years. A study conducted by B. Pohl in 1992, found that raccoons were able to tell the difference between identical and different symbols, after only a short learning period, and could still do this for three years after the initial learning session.