In all creation, only humans engage in prayer because only humans are capable of being aware of their own mortality, vulnerability, dependence and weakness. Ironically, it is only humans who strive to prove otherwise. Unfortunately, religion has made prayer something other than what it is by formalizing it into a religious duty or penance.
Prayer is conversation.
At its most fundamental level, it is the created seeking help from the Creator, the powerless seeking the Powerful, the dependent seeking and conversing with the Dependable. Clearly, the prayer he gave us to pray is for our spiritual and physical benefit, rather than to please him. God is everywhere. In our familiarity with him, Jesus did not want us to forget that he is all-powerful. Asked in faith, we can then experience the peace that comes from knowing we are secure in his care.