Some people have been told that snakes, before they drink water, “release” their poison into a sack then after drinking they retrieve the sack.  If they don’t find their sack them kill themselves.  Well, this is not true at all and snakes are Venomous not poisonous. Snakes can however control the venom they inject as they are older but the venom sacks can not be removed (unless surgery). Snakes drink water and eat their food fine without any problems from their venom-sacks.