There are several ways that a snake can defend itself: Some try to scare off danger with warnings: Actual rattles or tail-vibrating in grass or leaves (bull snakes are a type that does this. It can sound like a rattlesnake) and maybe make danger shy off. Hissing, gaping and striking are also warnings. The inner lining of a Water Moccasin's mouth is white and is used as a warning sign. The hog nosed snake uses the ploy of 'apparently dead and rotting' to encourage would be snake-munchers to go away. It rolls over on it's back, gaps it's mouth open and emits a smell that is decidedly unappetizing. The hog nose does take it's death scene a little too far, though. If it is rolled over onto it's belly, it often times, rolls back belly-up. There are those that use speed (i.e. Red racer) who can move fast enough to reach shelter before whatever reaches them. One tree snake jumps out of danger and 'flies' to the ground or to another tree, Not surprisingly, it's Called a Flying Snake. Snakes that use venom use it when there is no other choice. Danger has come too close. SInce each only has a limited supply of that venom, it is used as a last resort, be the snake the a Copperhead or a Spitting cobra. The only snake I have ever heard of that will chase someone is either the Green or Black Mamba, I can't remember which.
