Being a complete atheist, who doesn't believe in a soul and has doubts about even whether true consciousness exists, I obviously do not feel snakes are evil. From a completely objective standpoint, something would have to have the capacity to at least reason and subscribe to some generally accepted ethos. Not to mention, good and evil is simply a matter of perception. Strictly on an objective basis, I think you can make a much better argument that a person who drives an SUV is evil.