A boy scout says to his scout leader, "Sir, is this snake poisonous?" The scout leader says, "No, that snake's not poisonous at all." So the boy picks up the snake, which bites him and the boy starts to spasm and foam at the mouth as the other kids look on in horror...
The scout leader says, "But that snake is venomous. Poison is ingested or absorbed, while venom is injected. Let's get it right next time, boys."