between a napix and a true mocassin.
BD,
I can tell from 40 yards away, as I did this little female here.
The first pic:
http://webpages.charter.net/bobad/picture004a.jpg shows the unmistakable white mouth. Mocassins simply open their mouth and quietly display. After the photo shoot, she quieted down, kept trying to crawl away, and completely quit offering to bite. How boring! This is typical mocassin behavior.
Common brown water snakes hiss, strike, posture, and really put on a fearsome show. A gravid female water snake is REALLY MEAN, and will actually chase you.
The second pic
http://webpages.charter.net/bobad/picture003a.jpg clearly shows the pit, the vertical pupil, and the horny brow over the eye, which are unmistakable marks of pit vipers.
To all: Moccasins are wary and shy, and will dive in the water and disappear before you get within 20 yards of them. I have never seen more than 2 or 3 in a day. Do I like them? No. Am I afraid of them? No. There's just no reason to be afraid of them under normal circumstances.
