Water moccasin is a vernacular name for the cottonmouth, according to the Smithsonian National Zoological Park. The cottonmouth gets its name from the unusual adaptation of opening its fanged mouth when threatened, exposing a white inside. Cottonmouths are strong swimmers and have even been known to swim across short stretches of ocean to reach barrier islands off the coasts of Florida. An adult cottonmouth is an average of 3 feet long, thick through the body and can be aggressive. The juveniles are banded with dark borders and paler centers and have yellow tail tips. They shake their colorful tails to attract prey like frogs and other small creatures. The coloring and the tails fade with age; but the young cottonmouth water moccasins do resemble copperhead snakes.
Copperheads have a distinctive copper-colored head, thick bodies and coppery, sienna or reddish-brown bodies with dark border markings. Adults may shade into gray. The snakes have the cats-eyes of all pit vipers and the same pits near the eyes and nostrils that sense the movement of their prey. The University of Georgia's Savannah River Ecology Lab points out that a copperhead's camouflage is extremely effective. The snakes resemble a pile of the leaves or underbrush in which they hide. Juvenile copperheads also have a yellowish tail like cottonmouths, and they also use it as a lure for prey.
You can easily mistake a juvenile cottonmouth for a copperhead, unless you are foolish enough to move in closely to examine it. Both snakes have very similar coloring and markings, are thick-bodied and inhabit some of the same regions. One distinction is that copperheads have two black spots on the back of the head toward the middle that cottonmouths don't have. In Florida, you will only find copperheads in two northwestern counties near the Apalachicola River, but the snake can be found elsewhere throughout the central and eastern states. The cottonmouths also live along the eastern seaboard as far north as Virginia. In general, cottonmouths live closer to bodies of water while copperheads prefer forested woodlands near water, although both snakes can swim.
You don't want to make the acquaintance of either snake too abruptly. They each have a retractable set of fierce fangs that extend out the edges of their mouths automatically when the mouth is open. A pit viper bite is two serious puncture wounds that should be treated at once. The Suncoast Herpetological Society says you probably won't die from copperhead or cottonmouth venom but you could.The venom is a hemotoxin; it destroys red blood cells and blood cell walls. Even newborn pit vipers have fully toxic and functional tubular fangs. Your risk for snakebite increases during mating seasons in spring and fall when male snakes are particularly aggressive.
