While visiting southern Illinois I have occasionally come across this semi-aquatic serpent.
They are heavy bodied with greenish-brown to brown hues and a dark net-like pattern formed by dark blotches along the back, with each spot being vaguely diamond-shaped. The blotches are connected by alternating dark bars on sides.
Diamondback Water Snakes are non-venomous, but they can be extremely aggressive when cornered, striking and biting continuously until the danger goes away. Adults are typically three to four feet long.
Their range tends to be concentrated along the Mississippi River, as well as west into Texas and Mexico, east to Alabama, with smaller populations in Oklahoma, Kansas and Missouri.
A diurnal hunter, the Diamondback Water Snake trolls shallow shorelines and deeper water for prey. The diet mostly consists of frogs, toads, slow moving and small fish, which are eaten live. Carrion is also a common part of their diet.
Like other North American water snakes, the Diamondback Water Snakes give birth to live offspring, producing 20 or more babies in the late Summer or early Fall.