The water moccasin (a.k.a. cottonmouth; Agkistrodon piscivorus) is a venomous snake of the American South. The adults come in the dark colors of moss and mud and may reach six feet. They live in water and are so adapted to the aquatic lifestyle that hatchling moccasins use their tails as fishing lures. Moccasins are as viable in salt water as in fresh, and an agricultural drainage ditch will serve almost as well as a lake or river. They bask on floating logs and brush, on the bank, and on rocky ledges uphill from the water. If a water hole dries up, they will migrate to find another. For aquatic animals, they're tolerant of dry weather. When a moccasin isn't hunting on land or in water or basking in the sun, it's often lying quietly in the shade.
People most often get bitten when they step on a moccasin. Occasionally a swimmer gets bitten. Moccasins may frighten attackers (and even people who accidentally come close to them) by yawning wide to show the inside of their pinkish-white mouths. They may, on the other hand, simply bite—in the air or under water. One victim who was bitten near the spine while swimming spent the rest of his life in a wheelchair. Researchers say half of all moccasin bites result in fingers or toes crippled by gangrene. But deaths are rare.