Garter snakes do bite people if provoked, but the bite is considered harmless, as they are non-venomous. The snakes have small teeth that can penetrate the skin and draw blood, but their mouths and teeth are usually too small to cause any serious injuries.
Although they are considered non-venomous research shows that garter snakes and most all other non-venomous snakes actually produce extremely small amounts of toxins in their saliva. However, this toxin has no effect on humans. In garter snakes, it works to stun the snake's prey, immobilizing the prey to make it easier for the snake to kill. These snakes eat a wide variety of prey, including birds, fish, insects and amphibians. In addition to biting, garter snakes have a few other defense mechanisms that they use to deter predators. These include defecating and emitting a foul-smelling substance.
Many different species of garter snakes are found throughout North America, including numerous subspecies of both Plains and common garter snakes. These snakes are generally quite small and thin, with no species growing over 4 feet in length. Garter snakes come in a wide variety of different colors, including green, yellow, blue, red, orange and gold. Black and brown garter snakes are also quite common.