Garters were long thought to be nonvenomous, but recent discoveries have revealed that they do in fact produce a mild neurotoxic venom. Garter snakes are nevertheless harmless to humans due to the very low amounts of venom they produce, which is comparatively mild, and the fact that they lack an effective means of delivering it. They do have enlarged teeth in the back of their mouth, but unlike many rear fanged colubrid snakes, garter snakes do not have a groove running down the length of the teeth that would allow it to inject venom into its prey. The venom is delivered via a duvernoy's gland, secreted between their lips and gums. Whereas most venomous snakes have anterior or forward venom glands, the Duvernoy's gland of garters are posterior (to the rear) of the snake's eyes. The mild poison is spread into wounds through a chewing action. The properties of the venom are not well known, but it appears to contain 3FXT, commonly known as three-finger toxin, which is a neurotoxin commonly found in the venom of colobrids and elapids. A bite may result in mild swelling and an itching sensation. There are no known cases of serious injury and extremely few with symptoms of envenomation.