Understanding the visual cues of snakes is important for safety when encountering them in natural environments. While general characteristics can suggest a snake is venomous, definitive identification requires careful observation of several features. Many harmless snakes resemble their dangerous counterparts, making accurate recognition crucial for safe interaction.
Key Distinguishing Features
Many venomous snakes, especially pit vipers, share physical traits that distinguish them from non-venomous species. Their heads are often triangular or spade-shaped due to venom glands. Non-venomous snakes typically have more rounded heads, not distinctly wider than their necks.
Pupil shape is another distinguishing feature. Most venomous snakes, except coral snakes, have vertical, elliptical pupils. Non-venomous snakes typically possess round pupils.
Pit vipers, including rattlesnakes, copperheads, and cottonmouths, also have specialized heat-sensing pits. These small depressions are located between the eye and nostril, allowing them to detect warm-blooded prey. These pits are absent in non-venomous snakes.
Common Venomous Snakes and Their Unique Marks
Rattlesnakes are recognized by the distinctive rattle at the end of their tail, made of interlocking keratin segments that produce a buzzing sound. Their bodies are often heavy and display various patterns, such as diamonds or blotches, depending on the species.
Copperheads typically have a pale tan to brown body with darker, hourglass-shaped crossbands. These bands are wider on the sides and narrower along the spine. Their heads are often coppery-tan, giving them their name. Juvenile copperheads may have a bright yellow tail tip, which fades as they mature.
Cottonmouths, also known as water moccasins, are dark-colored, heavy-bodied snakes found in or near water. When threatened, they display a pale or white mouth lining, giving them their name. These snakes have broad, blocky heads and a dark stripe often runs through their eyes. Younger cottonmouths have more distinct banding and a bright yellow tail tip, which they use to lure prey.
Coral snakes are known for their bright, alternating bands of red, yellow, and black. A common rhyme, “red on yellow, kill a fellow; red on black, venom lack,” helps differentiate them: venomous coral snakes have red bands touching yellow bands. Unlike pit vipers, coral snakes have small, rounded heads not much wider than their necks, and they possess round pupils.
Mimicry and Look-Alikes
Many non-venomous snakes mimic venomous species as a defense, making identification challenging. For example, the non-venomous Scarlet King Snake resembles the venomous Coral Snake. Both have red, yellow, and black bands, but on Scarlet King Snakes, red bands touch black, while on Coral Snakes, red bands touch yellow.
Several harmless water snake species can be mistaken for the venomous Cottonmouth. Water snakes have more slender bodies and round pupils, and their heads are not as broad as a cottonmouth’s. When threatened, water snakes may flatten their heads to appear more triangular, adding to the confusion. Bullsnakes and gopher snakes can mimic rattlesnakes by vibrating their tails in dry leaves or grass, creating a similar sound, and flattening their heads. The Eastern Milksnake and juvenile black rat snakes can also be confused with copperheads due to similar patterning.
Important Considerations and Cautions
Snake appearance varies by age, geographic region, and individual variations, making identification challenging. Juveniles may have different coloration or patterns than adults. Relying on a single characteristic can lead to misidentification.
Behavioral cues, such as rattling or defensive postures, can offer clues. However, some non-venomous snakes mimic these behaviors, so they should not be the sole basis for identification. When encountering any snake, regardless of its perceived venomous status, give it space and leave it alone.
Maintaining a safe distance of at least five feet is advisable. If a snake is found in an undesirable location, such as inside a home or high-traffic area, contacting local animal control or a professional wildlife removal service is the safest course of action. These professionals can safely manage the situation.