What does the poet Theodore Roethke find so special about the form of the snake in the poem 'Snake'?

The poem, "Snake," by Roethke reveals some fascinating and special aspects of his poetry.  The first would be the naturalism that the snake holds.  In the first stanza, the poet's use of natural descriptions make the snake come alive.   The "molted shade" gives us a different view of how the snake is viewed.  Whereas the traditional conception of snake is one of sinister and devious motives, this depiction presents the snake in a different light.  The manner in which the snake stays in the "still air," and how the snake does not really bother or intrude on anyone.  It seems as if the snake is at peace with the world, as it has achieved a type of balance with the natural world and its sense of self.  Once again, this contrasts with the typical Western depiction of snakes.  As far back as the serpent in the Garden of Eden, snakes have been portrayed as elements that seek to destabilize their natural settings.  Yet, here we see a vision of a snake at peace with elements around it.  It can remain "in the still air" and then, in an instance, result in being "gone."  Roethke admires its purity and its sense of self in this environment.  There seems to be a longing in the speaker's voice for the simplicity offered by the snake and its interaction with the world.  The idea of "sensuousness" is also special for the speaker.  When the poet describes the snake as being of a "sensuous form," I think the speaker is trying to indicate how in sync the snake is within its environment. It seems like the snake is well centered and within a niche where there is absolute comfort between the snake and its world.  This is the hope of the speaker, of Rothke, and this might be what he finds so special about the snake.  The theme of naturalism is prevalent in Roethke's poetry and he seems to be creating a setting where the snake and naturalism converge into one.