Snakes are tough and they can't be defeated!! Just kidding, snakes can't destroyed, but there is a strategy to help you fight them off:
Making a match that includes a stone a snake has wrapped around will cause that snake to move to another area of the game board. Snakes move randomly, so there is no way to predict where it'll jump to next.
There's a few additional strategies you can use to make a snake move, like the Rainbow booster and selecting a gem that a snake is currently on, this will cause all the snakes on those gems to move. Also, boosters that clear out rows or columns, will also force a snake to move if the blast from the booster hits them.