Black and white snakes, with their striking patterns, are found globally in diverse environments like forests, deserts, and marine ecosystems. Accurate identification is important, as this coloration appears in both harmless and venomous species.
Harmless Black and White Snakes
Many black and white snakes are non-venomous and play important roles in their ecosystems. The Eastern Kingsnake (Lampropeltis getula), also known as the “chain kingsnake,” has a glossy black body with distinctive white or yellow chain-link crossbands. These constrictors typically grow 90–122 cm (36–48 in) long and inhabit diverse environments across the eastern United States. Eastern Kingsnakes prey on rodents, birds, and other reptiles, including venomous snakes like copperheads and rattlesnakes, due to their resistance to pit viper venom.
The California Kingsnake (Lampropeltis californiae) also exhibits black and white banding or stripes. Found across the western United States and parts of Mexico, this species typically reaches 60-150 cm (2-5 feet) and occupies diverse habitats like grasslands, deserts, and woodlands. Like other kingsnakes, they are constrictors that feed on small mammals, lizards, and other snakes, including rattlesnakes. Milk Snakes (Lampropeltis triangulum), another non-venomous group, can display black and white banding, often with red. They mimic venomous coral snakes through Batesian mimicry and help control rodent populations.
Potentially Dangerous Black and White Snakes
Several black and white snake species possess potent venom and warrant caution. The Banded Sea Krait (Laticauda colubrina), also known as the yellow-lipped sea krait, is a highly venomous marine snake. Identified by its black and white or bluish-grey bands and a flattened, paddle-like tail, it is widespread in tropical Indo-Pacific waters. These amphibious snakes hunt in coastal waters but return to land to digest, rest, and reproduce. Their neurotoxic venom affects the nervous system, causing paralysis and respiratory failure, though they are generally not aggressive unless provoked.
The Common Krait (Bungarus caeruleus), found in South Asia, is a highly venomous terrestrial snake with a black or bluish-black body and narrow white crossbands. This nocturnal species typically grows 0.9-1.75 meters (3 to 5.7 feet) and inhabits grasslands, agricultural fields, and human settlements. Its extremely potent neurotoxic venom makes it one of the “Big Four” snakes responsible for many medically significant bites in South Asia. Some Mojave Rattlesnakes (Crotalus scutulatus) can also display black and white patterns. This pit viper, found in the southwestern United States and Mexico, possesses a highly toxic venom with both neurotoxic and hemotoxic effects.
Identifying Key Differences
Distinguishing between harmless and dangerous black and white snakes requires careful observation, as no single characteristic is entirely reliable. Venomous pit vipers, like rattlesnakes, often have a triangular head and elliptical pupils, unlike the rounder heads and pupils of many non-venomous species. However, non-venomous snakes can flatten their heads when threatened, and pupil shape changes with light. A rattle at the end of the tail clearly indicates a venomous rattlesnake.
For banded snakes resembling coral snakes, a common rhyme in the United States is: “Red on yellow, kill a fellow; red on black, venom lack.” This suggests venomous if red bands touch yellow, and non-venomous if red touches black. However, this rhyme is not universally accurate and can be misleading outside the U.S. or with aberrant patterns. Coral snakes generally have a black snout and bands that encircle the body, while mimics often have a red snout and incomplete banding.
What to Do When You See a Snake
Encountering a snake can be startling, but remaining calm and maintaining a safe distance is crucial. Snakes generally prefer to avoid human interaction and will move away if given the opportunity. Avoid sudden movements that might startle the snake, and never attempt to capture, provoke, or harm it, as most bites occur during handling. Back away slowly, giving the snake ample space to retreat.
If a snake is in an undesirable location, such as inside a home or yard, contact local animal control, a wildlife expert, or a professional snake catcher. If a bite occurs, seek immediate medical attention by calling emergency services (such as 911 in the U.S.). While waiting for help, keep the bitten area still and lower than the heart, remove any jewelry or tight clothing before swelling, and clean the wound with soap and water. Do not cut the bite, suck out venom, apply a tourniquet, or use ice, as these actions can cause more harm than good.