How to Identify Kentucky’s Venomous Snakes

The venomous snakes native to Kentucky are limited to the copperhead, Timber Rattlesnake, Western Cottonmouth, and the Pygmy Rattlesnake (in the order of their concentrations in the state). These venomous snakes have four distinct traits that make them easily identifiable from Kentucky’s non-venomous snakes.

The Four Traits of Kentucky’s Venomous Snakes

Vertical Pupils

In Kentucky, the venomous snakes are distinguishable from those in many other states due to their vertical (cat-like) pupils. There are no native venomous snakes in Kentucky that possess round pupils; all native venomous species have these distinctive cat-like pupils, and all non-venomous snakes in Kentucky have round pupils (see image below).

Sensory Organs

Kentucky’s four venomous snakes also possess unique sensory organs that enable them to locate warm-blooded prey, distinguishing them from non-venomous snakes in the state and many venomous snakes found in other states. These sensory organs, known as “pits,” are small openings located on either side of the head, positioned just below and between the nostril and the pupil (as shown in the image below). The presence of these distinctive organs classifies the snakes as “pit vipers.”

Tail Scales

Another distinguishing characteristic of Kentucky’s venomous snakes is a little less obvious, that is, unless you’re getting way too close! This characteristic is found on the scales underneath the snake’s tail. But don’t go grabbing snakes by their tails to see… they can switch back quickly and bite! In Kentucky’s venomous snake populations, the tail is characterized by a single, undivided row of scales after the anal plate (pictured below). In contrast, non-venomous snakes have a double row of scales below the anal plate.

Live Birth

The final distinguishing characteristic in learning how to identify Kentucky’s venomous snakes is their young. All four of Kentucky’s venomous snakes give birth to live young, making them viviparous. No venomous snake eggs should ever be found in the wild in Kentucky.

The Two Misleading Traits of Kentucky’s Venomous Snakes

There are two common characteristics that many people associate with Kentucky’s venomous snakes, which are often deceiving and incorrect.

Their Distinctive, Triangular Head Shape

Kentucky’s venomous snakes indeed have a triangular-shaped head (typical of pit vipers) that is larger at the base than the neck; however, many other species can mimic this head shape when threatened, making their head look much like a pit viper’s. Additionally, venomous snakes positioned in a way that their head is not visible could give a false impression that they are non-venomous snakes.  Due to the mimicking and potential for poor visibility of the head, identifying a venomous snake solely by its head shape is misleading. It could lead to potentially harmful bites or the unnecessary killing of non-venomous species.

Tail rattling

Since Kentucky has only two rattlesnakes, the remaining two venomous snakes cannot be identified by their tail rattling. Furthermore, many non-venomous species mimic the rattlesnake’s rattle by rapidly whipping or vibrating their tails when alarmed or threatened. Of course, this will not produce the iconic rattlesnake rattle, but it will emit a buzzing sound that may scare individuals who are unfamiliar and uneducated about Kentucky’s snakes. Additionally, in dry vegetation, this rattling may sound even more like that of a rattlesnake.