Bright colors are an effective defense mechanism used by animals to signal danger. For people who spend time outdoors, a simple mnemonic device helps distinguish the deadly coral snake from its harmless look-alikes. This common rhyme is a tool for rapid identification of the highly venomous coral snake. Since coral snakes possess a potent neurotoxic venom, accurate identification is a matter of public safety.
The Mnemonic Rhyme Explained
The most widely circulated version of the rhyme in the United States uses the sequence of the snake’s colored bands as the main identifier. The core message is: “Red on yellow, kill a fellow; red on black, venom lack.” This refers to how the colored rings touch each other along the snake’s body. The rule states that if a red band is directly touching a yellow band, the snake is the dangerously venomous coral snake.
Conversely, the rhyme suggests that if a red band is touching a black band, the snake is a non-venomous mimic, often a king snake or scarlet snake. The rhyme’s specific wording communicates that venom is either present (“kill a fellow”) or absent (“venom lack”) based on the color pattern. This simple rule of color adjacency is relied upon for quick differentiation in the field.
Identifying the Snakes Involved
The rhyme highlights the difference in banding patterns between the venomous Eastern Coral Snake and non-venomous mimics like the Scarlet King Snake and Scarlet Snake. The Eastern Coral Snake features alternating rings of red, yellow, and black. The red bands are separated from the black bands by a narrow yellow band, and the rings completely encircle the body. It also has a characteristic black snout.
In contrast, the non-venomous Scarlet King Snake exhibits a pattern where the red bands touch the black bands, separating the yellow or white rings. While the king snake’s rings typically encircle the body, its snout is usually red. The Scarlet Snake, another mimic, has a similar color pattern, but its bands do not completely circle the body; its underside is plain white or light. The coral snake’s tail section is unique, often featuring only black and yellow bands.
Important Regional Caveats
While the mnemonic is a popular tool, relying on it carries significant risk because its accuracy is strictly limited by geography. The rhyme is generally considered reliable only within the range of the Eastern Coral Snake and the Arizona Coral Snake in the Southern and Eastern United States. Outside of these regions, particularly south of the U.S. border into Mexico and Central America, the rhyme often fails.
There are over 80 species of coral snakes across the Americas, and many have color patterns that violate the rhyme’s rule. Some venomous species outside the US may have red bands touching black bands, incorrectly identifying them as harmless. Even within the US, snakes can display color variations, or juveniles may have patterns difficult to interpret. For example, the non-venomous Sonoran Shovel-Nosed Snake in Arizona has red and yellow bands touching, further complicating identification.
Immediate Action Following a Bite
A suspected coral snake bite must be treated as a medical emergency requiring immediate attention, even if symptoms are not yet apparent. Coral snake venom is primarily neurotoxic, affecting the nervous system and causing delayed symptoms like muscle weakness, difficulty breathing, and paralysis. Call emergency medical services immediately and remain calm to prevent the rapid spread of venom.
The affected limb should be immobilized and kept at or below the level of the heart to slow the venom’s circulation. Remove any tight clothing or jewelry from the affected area before swelling begins. Traditional first aid methods are explicitly discouraged:
- Applying a tourniquet.
- Cutting the wound.
- Attempting to suck out the venom.
- Applying ice.
Treatment at a medical facility typically involves observation and the possible administration of antivenom.