Snakes alive! Encountering northern watersnakes in southwestern Connecticut

On a nature hike in a public park in New Canaan, Conn., this weekend, our family saw two northern water snakes, one of which was feasting on a frog. How cool is that?
I initially assumed they were poisonous copperhead snakes, but after reviewing photos and descriptions online, I’ve concluded they were the more common, non-venomous northern water snake. (See "Snakes In Connecticut" by the Connecticut Department of Environmental Protection.)
When I approached one of them with a net we using to catch frogs to examine, the snake lunged at the net. It momentarily got its fangs stuck on the netting. It didn’t want to be messed with. So we left it alone. Same thing with the other snake.
But we did snap some photos of the two with my cell phone.