Many people mistakenly believe that a snake’s eye shape reliably indicates if it is venomous. The common myth suggests round pupils mean a snake is harmless, while slit-like pupils signify danger. This simplification is inaccurate and can lead to dangerous misidentifications. Relying on eye shape alone for identification can have serious consequences. This article aims to clarify this myth and provide more accurate insights into snake identification and safety.
Why Eye Shape is Not a Reliable Indicator
Numerous venomous snake species possess round pupils, making this rule unreliable. Highly venomous snakes like coral snakes, mambas, and cobras all have round pupils. Nearly all members of the Elapidae family, which includes some of the deadliest snakes globally, also have round pupils.
Conversely, some non-venomous snakes can have elliptical or cat-like pupils. Pupil shape is more closely related to a snake’s activity patterns, such as whether it is nocturnal or diurnal, rather than its venom status. Observing pupil shape alone is not a dependable method for distinguishing between venomous and non-venomous snakes.
Other Clues for Identifying Venomous Snakes
While no single trait is foolproof, some physical characteristics can suggest a snake is venomous. Head shape is often cited, with many venomous snakes, particularly pit vipers, having a distinctly triangular or spade-shaped head due to large venom glands. However, many non-venomous snakes can flatten their heads when threatened, mimicking this triangular appearance to deter predators.
Pit vipers also have heat-sensing pits, which are small, deep indentations located between the eye and nostril. These pits allow the snake to detect infrared radiation, or heat, from warm-blooded prey. Some non-venomous boas and pythons also possess similar heat-sensing structures.
Fangs are another distinguishing feature of venomous snakes, designed for venom delivery. However, these are typically not visible unless the snake is striking or its mouth is open, making them impractical for identification from a safe distance. Venomous snakes have specialized fangs, which can be fixed and hollow like those of cobras, or hinged and retractable like those of vipers.
Scale patterns and coloration can be highly variable, and mimicry by non-venomous snakes often complicates identification based on color alone. For instance, several harmless snakes mimic the bright banding patterns of venomous coral snakes. Rattlesnakes are identified by a rattle at the end of their tail, although many non-venomous snakes may shake their tails when agitated, which can sound similar if rustling in dry leaves.
The Complexity of Snake Identification
Accurately identifying snakes presents numerous challenges, extending beyond simple visual cues. Mimicry is a significant factor, where non-venomous species evolve to resemble venomous ones, making visual differentiation difficult. This evolutionary advantage helps harmless snakes deter potential predators.
Variability in appearance within the same snake species, including differences in color, pattern, and size, further complicates identification. Juvenile snakes can also look different from adults, and regional differences mean identification rules may not be valid everywhere. Snakes often move quickly or are observed from a distance, making detailed visual inspection unsafe or impossible. Definitive snake identification typically requires expert knowledge and should not be attempted by untrained individuals.
Safety When Encountering Snakes
When encountering a snake, prioritizing safety over identification is paramount. The most important rule is to leave the snake alone; never approach, handle, or provoke any snake, and always assume it could be venomous. Maintain a significant distance, ideally at least six feet, from the snake.
If you find yourself too close, slowly and calmly back away without making sudden movements. Never attempt to pick up, move, or kill a snake, as even a seemingly dead snake can still strike due to reflexes. If a snake is in an undesirable location, such as inside a home, contact local animal control or a professional snake removal service rather than attempting to manage it yourself.
In the unfortunate event of a snakebite, remain calm and immediately call emergency services. Keep the bitten area still and, if possible, position it below the level of the heart to help slow the spread of venom. Remove any rings, watches, or constrictive clothing from the affected limb before swelling occurs.
Do not attempt to cut the wound, suck out the venom, apply a tourniquet, or use ice, as these actions can cause more harm. Clean the bite area gently with soap and water and cover it with a clean, dry dressing while awaiting medical help.