The Milk Snake is scientifically classified as a type of King Snake. Both snakes belong to the same genus, Lampropeltis, a group of closely related New World constrictors. The genus Lampropeltis literally translates to “shiny shield,” referring to their smooth, glossy scales. While all Milk Snakes are King Snakes in the broad scientific sense, the Common King Snake (Lampropeltis getula) and the Milk Snake (Lampropeltis triangulum) are distinct species.
The Shared Family Tree
The scientific classification establishes the Milk Snake within the King Snake group. Both the Milk Snake and the Common King Snake share the genus Lampropeltis, which is the scientific name for all King Snakes. This genus is a collection of non-venomous constrictors found across North and Central America. Lampropeltis includes about 26 recognized species, with the Milk Snake (L. triangulum) being one of the most widespread.
The Milk Snake (Lampropeltis triangulum) currently contains fewer recognized subspecies than in the past, though it remains highly variable. The name “King Snake” is often used to refer to any snake within the Lampropeltis genus. This shared ancestry means they share many fundamental biological traits.
Key Characteristics of the Milk Snake
The Milk Snake (Lampropeltis triangulum) has an impressive geographic reach, spanning from southeastern Canada south to northern South America. This extensive range has resulted in numerous color variations, once classified as up to 24 different subspecies.
Milk Snakes typically display a pattern of red, black, and white, yellow, or orange rings or blotches. The pattern usually involves dark-bordered blotches running down a gray or tan body, often being red or reddish-brown in adults. In many subspecies, this colorful pattern is an example of Batesian mimicry, closely resembling the venomous Coral Snake.
Milk Snakes are medium-sized, reaching between 24 and 52 inches in length. They are primarily nocturnal and seek shelter in diverse habitats, including forests, rocky areas, meadows, and suburban parks. Their diet mainly consists of small rodents, birds, lizards, and reptile eggs.
Key Characteristics of the King Snake
The Common King Snake (Lampropeltis getula) is distinguished by its coloration and a unique dietary trait. These snakes often display dark bodies, typically black or dark brown, with a pattern of white or yellow bands, rings, or a chain-like appearance. They are non-venomous constrictors, but their common name refers to their habit of preying on other snakes.
This specialized diet, known as ophiophagy, includes consuming non-venomous snakes and venomous species like rattlesnakes and copperheads. Common King Snakes possess a natural immunity to the venom of native pit vipers, allowing them to hunt this dangerous prey. They are found in diverse habitats, and their powerful constriction helps them subdue their prey. Like Milk Snakes, they also feed on rodents, lizards, birds, and eggs.
Practical Identification and Common Mix-ups
Distinguishing a Milk Snake from a Common King Snake can be difficult due to the high variability within the genus Lampropeltis. Common King Snakes often have a chain-like pattern on a dark background, while Milk Snakes display a banded or blotched pattern. However, many subspecies and local variations complicate field identification. For instance, the Scarlet King Snake, a type of Milk Snake, shares the tricolor pattern that causes the most confusion.
The most common mix-up involves the venomous Coral Snake, which Milk Snakes often mimic. To distinguish the non-venomous mimics, a popular rhyme is cited: “Red on black, friend of Jack; red on yellow, kill a fellow.” This refers to the color sequence where red bands touch black bands on the harmless Milk Snake, while red and yellow bands touch on the venomous Coral Snake. However, this rhyme is not universally reliable due to geographic variations and the existence of other tricolored species.