Yes for snakes. And so the question about leather boots. Makes no sense to me to wear mesh boots with snake gaiters.The only reason to wear Turtleskin gaiters is for snake protection. I have both the gaiters and the chaps. Neither provide any protection in the lower part of the foot. What to wear under the gaiters was the conundrum for me.
I decided that I was going to wear footwear that would hopefully repel a strike so a full leather boot was my choice. I alternate between a Schnee Absaroka and Timberline. I am fully confident a Timber Rattler (the venomous snake in my area) would not pierce through the Absaroka leather. I am reasonably confident it would not pierce the Timberline.
I find the Schnee boots to be very comfortable, the gaiters fit over them nicely, and often forget the gaiters are on. I would recommend that you run paracord from the eyelets on either side of the gaiters underneath the boots and tighten them to keep the gaiters from rising up. You want them as low as possible.