Thanks, Egg. The pattern looked so "flashy" that I didn't think it could be a garter snake.
I've never seen them threaten to bite anything. I guess it felt trapped. But good to know it's not something to worry about.
Heard my girls chattering and found three of them all staring intently at this snake. We live in southern NH, and I've really only ever seen garter snakes. This guy was different-would probably only be about a foot long if stretched out, but he was striking out at them as they got close. Never...