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.