Is there a poison that gets rid of snakes?
No. Snakes feed almost exclusively on living prey, and will not, therefore, take poisoned bait. Placing noxious chemical agents such as mothballs and lime around yards may or may not deter snakes temporarily, and these agents create a health hazard to children, pets and other wildlife. Most chemical agents and pesticides that could be used to repel snakes are dangerous to humans as well, and have restrictions that make use by the general public prohibitive.