Coral Snake vs Scarlet Kingsnake: Spot the Difference

Key differences at a glance

The two snakes share the same three colors and much of the same range in the southeastern United States, so they are easily confused, especially in leaf litter or poor light. The table above summarizes the differences. In short:

• Ring order: coral snake red-yellow-black-yellow-red; kingsnake red-black-yellow-black-red.
• Snout: black on the coral snake, red on the kingsnake.
• Size: the coral snake is usually longer, while the kingsnake is the smallest of all kingsnakes.
• Danger: the eastern coral snake is highly venomous; the scarlet kingsnake is completely harmless.

These clues apply only to native snakes in the eastern US. Elsewhere in the Americas, coral snake patterns vary far more, as explained in does the “red touches yellow” rhyme work?

Ring order: where red touches

On an eastern coral snake, wide red and wide black rings alternate, and each is separated from the next by a narrow yellow ring. As a result, every red ring has yellow on both sides. The red rings are often speckled with black, and the tail has only black and yellow rings.

On a scarlet kingsnake, each red band is bordered on both sides by black, and the yellow band sits between two black bands. The red bands are usually the widest. Young scarlet kingsnakes have white instead of yellow, and the pale bands gradually turn shades of yellow, from lemon to orange, over the first few years.

This is the basis of the rhyme “red touches yellow, kills a fellow; red touches black, friend of Jack.” For native snakes in the Southeast it works, but it should only be used to identify a snake from a distance, never as a reason to pick one up.

Head and snout color

The head gives a second, independent clue. The eastern coral snake’s head is black from the tip of the snout to just behind the eyes, followed by a broad yellow band, so the front of the snake looks dark and blunt. The scarlet kingsnake has a red snout, followed by a black band.

This is the origin of the phrase “red face, I’m safe,” used for tricolored snakes east of the Mississippi River. The other common look-alike, the scarlet snake, also has a red snout, which is pointed and used for burrowing.

Size, shape and behavior

Eastern coral snakes are usually 50 to 80 cm (20 to 31 in) long, with a record of about 122 cm (48 in). Scarlet kingsnakes are smaller, usually 40 to 50 cm (16 to 20 in), and the largest on record measured about 76 cm (30 in). Both are slim, smooth-scaled snakes with small heads and round pupils, so head shape and eye shape do not help.

Their daily habits differ. Coral snakes are active mainly by day, especially in the morning, late afternoon and after rain, and they spend much of their time under leaf litter and in old burrows. Scarlet kingsnakes are mostly nocturnal. By day they hide under the loose bark of dead pines, inside rotting stumps and logs, or underground, and they are good climbers.

When disturbed, a coral snake often hides its head under its coils and raises its curled tail as a decoy. A scarlet kingsnake may thrash, vibrate its tail or try to bite, but its bite is harmless.

Venom versus constriction

The coral snake is an elapid, a relative of cobras, and it kills its prey with neurotoxic venom delivered through short fixed fangs at the front of its mouth. Its main prey are other snakes and slender lizards. Bites to people are rare, but they can be life-threatening; see how venomous are coral snakes?

The scarlet kingsnake has no venom. Like other kingsnakes, it seizes its prey and squeezes it in its coils. It has an unusually narrow diet, even for a kingsnake: studies of its stomach contents show it eats mostly skinks, especially ground skinks, plus some small snakes. Both species swallow their prey head first.

Why the kingsnake looks like a coral snake

The resemblance is an example of Batesian mimicry, in which a harmless animal is protected by looking like a dangerous one. Birds and mammals that have learned to avoid red, yellow and black snakes, or that avoid them by instinct, tend to leave the kingsnake alone as well.

Its scientific name reflects this. Elapsoides means “like Elaps,” an old genus name that once included the eastern coral snake. The mimicry is not perfect, since the colors are in a different order, but at a glance, and to a predator that hesitates for even a moment, it works well enough.

Where they live and where they overlap

The eastern coral snake lives on the coastal plain from southeastern North Carolina through South Carolina, Georgia and Florida, west to eastern Louisiana. The scarlet kingsnake shares most of this area, including all of Florida, but its range extends considerably farther north, into Virginia, Kentucky and Tennessee, where there are no coral snakes at all.

Both favor pine forests with sandy soil. People often find scarlet kingsnakes in spring, sometimes in swimming pools or under debris, and they are generally secretive. Florida residents meet both species; see snakes in Florida for the state’s other common snakes.

Other look-alikes: scarlet snakes and milk snakes

The scarlet snake (Cemophora coccinea) is a third red, black and yellow or white snake of the Southeast. It is usually 36 to 66 cm (14 to 26 in) long, and its red markings are saddles across the back rather than rings, leaving a plain whitish belly. It has a pointed red snout, and like the kingsnake its red patches are bordered by black.

Milk snakes (Lampropeltis triangulum and close relatives) are kingsnakes too. The eastern milk snake of the Northeast and Midwest is mostly gray or tan with reddish-brown blotches, but milk snakes farther south and in Mexico and Central America are often banded in red, black and yellow or white. The scarlet kingsnake was treated as a milk snake subspecies until genetic studies showed it is a distinct species. Despite the name, milk snakes do not drink milk from cows, an old farmyard myth.