One of the most important qualifications that separate human being from animals is his obligation and beliefs to immaterial issues. While these supernatural matters are not capable of being experienced or materially proved, they would play a key role in our life. Believing in one God, life after death and being responsible in front of God are the most important subjects that all religions are talking about. Until now, nobody claimed that some animals believed in life after death or some responsibility toward God.
From the other side, we have no nations or any group of human beings in the history without having some kinds of supernatural beliefs. Bedouin people believed in spiritualism, and worshipping was very common among them