Are Corn Snakes Venomous? How Corn Snakes Kill Prey

Corn snakes are nonvenomous constrictors

The corn snake belongs to the family Colubridae, the largest family of snakes. Many colubrids are completely harmless, a few are mildly venomous and only a small number are dangerous to people. Corn snakes belong in the first group: they have no venom delivery system of any kind.

Their teeth are small, sharp, solid and curved backward, arranged in several rows on the upper and lower jaws. Those teeth are designed for gripping. Once a corn snake has hold of a mouse, the backward curve makes it hard for the prey to pull free, and the snake can begin to coil around it.

Interestingly, the ancestors of rat snakes were probably venomous. Over millions of years, rat snakes evolved powerful constriction as their main way of subduing prey and lost any useful venom.

How corn snakes kill their prey

Constriction is often thought to work by crushing the prey or breaking its bones, or by slowly suffocating it. Research shows it is much faster and more efficient than that.

1. Strike and grab. The snake detects prey mainly by scent, then strikes and seizes it, usually near the head.
2. Coil. Within a second or two it throws one or more loops of its body around the animal.
3. Squeeze. Each time the prey breathes out, the coils tighten a little more. The pressure stops the heart from pumping blood properly.
4. Swallow. When the prey stops moving, the snake loosens its coils, finds the head and swallows the animal whole.

A 2015 study by Scott Boback and colleagues, working with boa constrictors and rats, found that constriction causes circulatory arrest: the heart can no longer move blood around the body, and the prey loses consciousness and dies within minutes. Corn snakes use the same basic method. Smaller prey such as lizards, frogs or nestling birds are sometimes simply swallowed without being constricted.

The swallowing itself is also remarkable. The lower jaw halves are connected by stretchy tissue, so a snake can work its mouth over prey wider than its own head, one side of the jaw at a time.

What happens if a corn snake bites you?

Wild corn snakes nearly always try to escape rather than bite. If someone picks one up, pins it or corners it, it may strike in defense. Because the snake is small and its teeth are tiny, the bite feels like a pinch or a scratch from a rose thorn and often leaves a horseshoe-shaped row of pinpricks.

A corn snake bite does not inject venom and is not medically dangerous. Anyone who has an unusual reaction after any animal bite should get medical advice. The simplest way to avoid bites is to watch wild snakes without handling them.

Defensive bluffs that make corn snakes look dangerous

Corn snakes have several ways of trying to look more threatening than they are:

• Tail vibration. A frightened corn snake may shake its tail rapidly. Against dry leaves this produces a buzzing sound that resembles a rattlesnake’s rattle.
• Coiling and striking. It may draw its body into an S-shape and strike, sometimes with its mouth closed.
• Musking. Glands near the base of the tail release a strong, unpleasant smell that may make predators let go.

None of these behaviors means the snake is venomous. They are bluffs meant to scare off foxes, hawks, raccoons or curious people.

Why corn snakes are killed as “copperheads”

The biggest danger in the relationship between corn snakes and people runs the other way. Across the Southeast, many harmless corn snakes are killed because they are mistaken for venomous copperheads. Both snakes have reddish or coppery tones and a pattern of darker bands or blotches, and both live in similar woods and fields.

Pupil shape and head shape are not always easy to see safely, so the best rule with any snake you cannot identify is to give it space. A full guide is in copperhead vs corn snake. If anyone is bitten by a snake that could be venomous, seek emergency medical help immediately or call 911 in the US.

Venomous, poisonous or neither?

People often use “venomous” and “poisonous” as if they meant the same thing. A venomous animal injects a toxin, usually by biting or stinging, while a poisonous animal is harmful to eat or touch. Corn snakes are neither: they have no venom and their bodies are not toxic. The difference is explained further in Is a snake venomous or poisonous?.