According to Rav Hirsch, the snake wanted Chava to follow her instinctual desires because that's what he, as an animal, knew to be honest and true. As a human, with an understanding of the difference between our instincts vs Gods words, was meant to recognize the snake as cunning.
Can you think of a time when you or a friend actively chose to follow what you/they were told to do rather than follow your/their instincts and/or desires? What guides our decisions, our instincts or what we're told is right? When do you trust your instincts and when do you trust what you're told?