The eastern milksnake is a brightly colored, medium-sized snake with smooth scales. The color can be quite variable. The ground color is white to pale yellow with a series of 20–30 red, orange-red, red-brown, or light brown dorsal blotches that are bordered by black.
The markings on the neck closest to the head and on the head are variable; often the blotch on the neck merges with a marking on the head to form a Y or U shape. There is usually a narrow marking between the eyes on top of the head and another narrow marking from each eye to the corners of the mouth. The snout is white or light gray.
The top of the head may be red or orange. The belly is usually white and boldly marked with black squares and rectangles. The dorsal (upperside) scales are smooth, and the anal plate (the last belly scale, which covers the anal opening) is single.
Here are some of the variations that occur in Missouri specimens of the eastern milksnake:
- Eastern milksnakes from a few northeastern Missouri counties may have light brown blotches that are bordered in black.
- There may be a row of smaller red, brown, or black markings along the sides between the larger dorsal blotches; however, these may be missing or very small on specimens from western or southwestern Missouri.
- An adult eastern milksnake collected in southwestern Benton County had a dark gray belly with some white to light gray from the chin to the underside of the neck.
- The red milksnake often is misidentified as a coralsnake, which is not found in Missouri. Coralsnakes have red bands bordered by yellow.
- Some other Missouri snakes have colors and patterns that may be somewhat reminiscent of the eastern milksnake, including the northern scarletsnake, variable groundsnake, and Great Plains ratsnake. Paying close attention to the color patterns, habitat, size, and distribution will help sort these out.
- The eastern milksnake's closest relatives in Missouri are the prairie kingsnake, speckled kingsnake, and eastern black kingsnake. All are in genus Lampropeltis, but none much resemble the eastern milksnake in terms of color or pattern.
- Finally, the western milksnake (Lampropeltis gentilis) might potentially be found in Missouri. Recent studies of the numerous subspecies of the milksnake group (Lampropeltis triangulum) has resulted in the possibility of the western milksnake occurring in western Missouri from Kansas City south to the Arkansas border. Some herpetologists maintain that the western milksnake occurs in the southern Kansas City area of Missouri and question the identification of milksnakes in southwestern Missouri. The western milksnake apparently can only be distinguished from the eastern milksnake (L. triangulum) by using molecular (DNA) methods and geographical distribution. Although this species likely exists along the border with Kansas, no published studies using molecular data have confirmed western milksnakes in Missouri.
Adult length: 24 to 35 inches; occasionally to 52 inches.
Habitat and Conservation
This species resides under rocks on open, sparsely wooded, south-facing, rocky hillsides, especially glades, as well as along the edge of forests with rocks and downed trees. Milksnakes have been found under piles of boards, rusting sheets of tin, or other discarded junk laying on or embedded in the ground.
Eastern milksnakes are active from April until late October. In spring and autumn, they are active during the day, but in summer, they become nocturnal.
They are secretive and seldom seen in the open. They generally do not bask in the sun but instead coil up under a large or flat rock and are warmed by their shelter rock as it is warmed by the sun. This secretive snake requires slightly damp places to hide and will usually take shelter alongside or under deeply embedded rocks or logs.
During hot weather in July, August, and September, this species will move underground in mammal burrows or under large rocks.
Winter dormancy is spent in rodent burrows, crevices along rocky hillsides, foundations of old buildings, and old wells and cisterns. It is common for milksnakes to overwinter with other snake species, including kingsnakes, ratsnakes, racers, and copperheads.
When first encountered, a milksnake will try to escape into thick grass, dead leaves, or under the nearest rock. If grabbed, it will strike at a hand and give off a short hiss as it strikes, it will vibrate its tail very rapidly, smear feces on the hand holding it, and at the same time release a smelly musk from glands at the base of its tail. Even after a specimen has settled down while being held, it will suddenly and deliberately open its mouth and just start chewing on a finger or loose skin between the fingers. Their bite is harmless; this is not a venomous species.
Eastern milksnakes prey on lizards, small snakes and their eggs, mice, voles, and shrews. This species will also eat the young of its own kind, as well as young venomous snakes. Milksnakes in other states have also been found to eat bird eggs and the young of ground-nesting birds. A Shannon County specimen was found to have eaten eight skink eggs.
All prey are killed by constriction except small reptiles, bird eggs, or newborn rodents, which are eaten as is.
Although populations of this species are considered secure in Missouri, this brightly colored snake is often illegally collected from rocky glades in the Ozarks due to demand for the pet trade. Unfortunately, illegal collectors not only take individuals from glades but often destroy the large, embedded rocks necessary for milksnakes and other reptiles to live.
From about 2003 until 2014, Missouri’s milksnakes were considered a subspecies (Lampropeltis triangulum syspila) and were referred to as the "red milksnake," one of nine subspecies in southern Canada and the United States. Now, several of the subspecies in the central part of North America have been consolidated into one taxon and called the eastern milksnake (L. triangulum).
Courtship and mating occur in the spring, likely from early April through May, and there could be some mating in the autumn as well. Egg laying occurs some 30–45 days after mating, with females laying their eggs in late May through early July. A clutch typically comprises some 7 or 8 eggs, with a maximum of about 24. In general, larger females will lay more eggs per clutch. The eggs adhere to each other. A female eastern milksnake will deposit her eggs where they will be secure and moist: under a large flat rock or pile of rotting tree bark, or inside a rotting log, stump, or old pile of sawdust. The eggs hatch during mid-August to early September.
Juveniles become sexually mature during or after their second years of life. Milksnakes are considered a long-lived species, with a wild-caught adult surviving to 21 years of age in captivity.
This is one of Missouri’s most beautifully colored snakes.
The common name for this group of medium-sized, harmless snakes, “milksnake,” was coined by early European settlers who saw them in or near barns and milk sheds and assumed the colorful snake was there to “steal milk” from a cow. This is a myth. These small constrictors were almost certainly found in barns because barns are frequently infested with mice. The snakes were likely in search of mice to eat. They have no interest in cows or milk.
Too often, humans have mistakenly identified this colorful and harmless species as a coralsnake, but that colorful and venomous species occurs in southeastern and southern states, not in Missouri. Our eastern milksnake has a white or yellowish background color that touches the black of their dorsal blotches, and it has white or gray on their nose. True coralsnakes have their yellow bands touching the red bands, and they have a black band on their nose. Again, coralsnakes do not occur in Missouri; the closest population is the Texas coralsnake (Micrurus tener), found in a few southwestern counties of Arkansas.
Eastern milksnakes are often found dead on Missouri’s roads and highways.
The genus name, Lampropeltis, is from Greek root words and means "shiny shield." It refers to the glossy, smooth scales on the upperside of the body.
As predators, eastern milksnakes control populations of the animals they consume.
As with many other predatory species, they can be preyed upon themselves by larger animals, including mammals and predatory birds. The eggs and young are especially vulnerable. Hawks and owls may be able to prey on milksnakes, but the snake’s secretive nature provides protection from aerial predators. Milksnake eggs and young are likely eaten by kingsnakes, other milksnakes, scarletsnakes, and racers, as well as raccoons, skunks, and badgers.
Milksnakes are not the only mice-eating animals that are attracted to barns. Ratsnakes and several other kinds of snakes, plus barn owls, cats, and skunks capture mice and rats in and around farm buildings and stored grain.