There are no poisonous snakes; only venomous snakes. Poison is ingested; venom is injected. Also, the identification of the pit viper species for immediate venom neutralization after a bite is no longer important as there is currently only one antivenin treatment widely available - Crofab, which is a polyvalent antivenin. Crofab is used for venom neutralization for bites from all North American pit vipers which include rattlesnakes, copperheads, and water moccasins. There are some experimental antivenins currently in clinical trials, but are not FDA approved as of yet. Supportive care after initial treatment using Crofab is a whole different story. Hope this helps.