Reptiles
Ring-necked Snake
Diadophis punctatus · also called ringneck snake
Lift a flat stone at the edge of an eastern woodland and you may uncover a snake barely thicker than a pencil, dark grey with a neat yellow collar. Pick up the cover too roughly and it will hide its head, twist its tail into a bright red corkscrew, and hope you think it is dangerous. It is not. It is a ring-necked snake, one of the most abundant and least seen snakes in North America.
Overview
Diadophis punctatus is a small, slender snake, usually 25 to 38 cm long, with a smooth slate-grey to blackish back, a yellow, orange, or cream ring across the neck, and an underside that runs from yellow to red and is often speckled with black. It ranges across most of the United States into Canada and Mexico, living in moist woodland, rocky slopes, and grassland edges.
The corkscrew bluff
Ring-necked snakes hunt earthworms, slugs, and salamanders, using a mild rear-of-mouth venom that is harmless to people. Their own defence is theatre: cornered, many tuck the head away and coil the tail into an upward spiral, flashing the bright belly as a warning, sometimes adding a pungent musk. The redder the belly in a population, the more strongly the snakes tend to do it.
Life under cover
This is a snake of hiding places — under rocks, logs, and bark, or in the damp soil just below the surface. It is mostly nocturnal and rarely seen despite being common. Ring-necked snakes are also unusually gregarious, with dozens or hundreds sharing a hibernation crevice, and they will actively choose a shelter that already holds other ring-necked snakes.
Status
The ring-necked snake is Least Concern and one of the most numerous snakes across much of its range. It is split into around 14 subspecies that likely represent several species; only some peripheral and island populations are of local concern.
Ring-necked Snake: common questions
Is a ring-necked snake venomous or dangerous?
Not in any way that matters to people. It does produce a weak venom, made in a gland at the back of the upper jaw and worked into small prey by chewing, which helps it subdue earthworms, slugs, and salamanders. But it has no front fangs, it almost never tries to bite a human, and its mouth is too small to do more than scratch if it did. There are no medically significant effects from a ring-necked snake on a person. Its real defences are hiding, musking, and the tail-coil bluff, not biting.
Why does a ring-necked snake curl its tail into a spiral?
It is a defensive display. When a ring-necked snake is exposed and cannot escape, it often tucks its head safely under its body and twists the end of its tail into a tight upward corkscrew, turning the belly outward so the sudden bright yellow, orange, or red shows. The likely message to a predator is that the animal is distasteful or dangerous, a bluff since the snake is neither, and the coiled tail also draws a strike away from the vulnerable head. Not every individual does it, and the behaviour is strongest in populations with the reddest bellies.
Where do ring-necked snakes live and why are they so rarely seen?
They live across most of North America in moist, cover-rich habitats — deciduous and mixed woodland, rocky wooded slopes, the edges of fields and wetlands, and older gardens and parks. They are genuinely common in many of these places. The reason people seldom encounter them is behavioural. Ring-necked snakes are small, secretive, and mainly nocturnal, and they spend their lives under rocks, logs, and bark or in the loose soil and leaf litter just below the surface, coming into the open only at night or after rain. Turning over flat stones and fallen wood is the usual way to find one.
Are ring-necked snakes really social?
More so than most snakes, though the picture is still being worked out. Large aggregations, sometimes of a hundred or more animals, are regularly found sharing the same hibernation crevice or the same rich foraging area under cover, and this is not simply because good sites are scarce. Studies have shown that individuals will choose shelters that already contain other ring-necked snakes over identical empty ones, which suggests active attraction to their own kind. Whether this amounts to true social structure, or just tolerance and shared preferences, is not settled.