Again, I don't encourage a Yorkie fighting a snake off, but also it's nice to know that they weren't afraid to take action. Like my signature says: Big things come in small packages, and I'm referring to the Yorkshire TERRIER!
Fabulous little dogs and it's because of this tenacity/sweetness and their stature that I love them so much. A very well balanced breed indeed when bred properly.
Don't let your furbabies fight off snakes, if they do, "Good job" and now watch them more closely to avoid it from happening again!!