Update: The photograph below (taken by my daughter) is now part of the Wikipedia article on Garter snakes, and is the best picture of a posterior tooth I’ve seen.

Garter snakes are probably the best known species of snake in the US. They are easy to recognize, and they occur just about everywhere in North America. Most people will tell you that garter snakes are harmless, which they are, but probably not quite as harmless as you might think.

Garter Snakes Have Pretty Big Teeth

The picture above is of the snake I recently caught which taught me that garter snakes have relatively large teeth. Although he was very aggressive, I caught him without being bitten, however while holding him, he managed to get one of his teeth into my thumb (I would have been more careful if I’d known what he was packing). For a moment, I thought I’d misidentified him, but his markings couldn’t have been more clear. I used a small stick to (very gently) open his mouth, and sure enough, he had two needle-sharp teeth in there. While doing some research when I got home, I discovered another surprising fact:

Garter Snakes are Venomous

It was recently discovered that the saliva of a garter snake contains a very mild neurotoxin. Rather than injecting it through fangs, they spread it into wounds (presumably caused by those teeth) through a chewing motion. Although the venom of a garter snake is only potent enough to cause some minor swelling or itching in a human, it can stun a toad or small rodent enough to make swallowing it much easier.

While I have your attention, here are three more interesting facts about garters:

1. They are the only species of snake in Alaska.
2. When threatened, they release a foul smelling musk. It’s not nearly as bad as the musk released by a northern water snake, but it will get your attention.
3. Garter snakes hibernate in great numbers. When they emerge, some males will release female pheromones which fool other males into trying to mate with them. The fake female steals the other males’ heat energy which he then uses to overpower other males and give himself a better chance of successfully mating — hopefully with an actual female.

You now know probably much more than you ever wanted to about garter snakes. The most important lesson, however, is that they are only aggressive when provoked (just like all snakes), so if you don’t like them, the best course of action is to simply leave them alone. If you do like them, however, watch those teeth as you pick them up.