Wake the serpent not—lest he
Should not know the way to go,--
Let him crawl which yet lies sleeping
Through the deep grass of the meadow!
Not a bee shall hear him creeping,
Not a may-fly shall awaken
From its cradling blue-bell shaken,
Not the starlight as he’s sliding
Through the grass with silent gliding.

Percy Bysshe Shelley

http://www.poemhunter.com/poem/wake-the-serpent-not/