I may get some flack from my feelings, but in my opinion, it's a SNAKE, and I don't like them. Whether they are poisonous or nonpoisonous I don't want them around me and my family (including our dog) when we are in the yard. I know they have a useful purpose, but they can fulfill their purpose somewhere other than where I am.
I have a shovel, and know how to use it.
From my understanding, a snake with a pointed/arrow shaped head is poisonous and those with a rounded head are not. Also the venom of a baby snake is more concentrated. At any rate, as far as my yard is concerned, refer to the last sentence in the first paragraph.

Breezie