Topping our list of smartest animals is another great ape, the chimpanzee. The impressive intellectual abilities of this animal have long fascinated humans. They can make and use tools, hunt collectively, and are capable of advanced problem-solving. They are also able to learn sign language to communicate with humans and can remember the name sign for individuals they have not seen for several years. But perhaps the most amazing feature of the chimpanzee is its ability to use symbols for objects and combine the symbols in a sequence to convey a complex idea. Such intellectual gifts are probably central to maintaining this animal's complex social groups, where they form strong bonds and observe elaborate hierarchical structure.