Chimpanzee male

Chimpanzees are true masters when it comes to solving puzzles and using tools. They build spoon-like rods to scoop out honey or crack open nuts using stones. To prevent hurting their fingers, they knuckle-walk. In doing so, they place only the middle phalanxes of their hands on the ground.

Fun fact: Chimpanzees are one of the only animals to recognise themselves in a mirror.