Don't only humans have the ability to use tools?
Humans are not the only animals who know how to use tools.
As one example, some tribes of chimpanzees use rocks to crack open nuts. Knowledge of how to do this is passed on from one generation to the next, as the young watch their elders.
This procedure requires using two rocks, one as an anvil, and one as a hammer. The process of selecting the right type of rock for the anvil and the right type of rock for the hammer, and the process of smashing a nut between them is one which is very tricky, and requires considerable practice. This was apparent when a human researcher studying the chimps tried to do this himself. It took him several hours to crack open his first nut, a process which takes experienced chimps only a few seconds.
Other tribes of chimpanzees of the same species have not discovered this cultural knowledge. The shells of these nuts are too hard too be opened with their teeth, and these other tribes therefore do not have these nuts as a part of their diet, even though both rocks and nuts are plentiful. As different tribes of chimpanzees interact, knowledge of varies types of tool use, such as this one, is transmitted from one tribe to another.
I find it particularly interesting to compare how new practices are spread in human and other primate societies. For example, there was a case where a young female macaque monkey discovered how to remove the sand off of fruit by washing the fruit in the river. The first monkeys in the community to copy the procedure were her mother and the other children. Later, the other adult females also began to wash their fruit. The absolute last group in the society to adopt the practice was the adult males, and I can not help but wonder if there are any parallels to human societies.
Follow up questions:
Don't only humans have the ability to use language and understand abstract concepts?
Aren't only humans self aware?
What evidence is there that other animals can make moral decisions?
Don't only humans understand the concept of death?
Don't only humans have the ability to enter social contracts?
How can some animal rights activists believe that other animals are our equals?