Most people are surprised to find out that the harmless Garter Snake is actually venomous. Now, before you get out the hoe and the shotgun, their venom is not dangerous to people. Like the rear-fanged snakes, Garter Snakes have Duvernoy’s glands, which secret a type 1 protein venom, which can cause discomfort and swelling, and usually causes no symptoms at all in people.