Why do hognose snakes have a “popping” tooth?

If snakes could enter cuteness contests, this one might win...

Not a hognose snake – black snake, photo by Mike Bell

Snakes tend to get a bad reputation, but they are beautiful creatures that have important jobs within the ecosystems where they live. I’ve already seen a rattlesnake this spring (near our house, but not AT it thank goodness) and the gorgeous black snake above, which climbed a bush to put some distance between itself and the members of our hiking club. If you take the time to think about it, it’s kind of remarkable they can skim along the ground and climb trees and rock faces without limbs to help them.

Many humans seem to have an innate fear of Mr. No-Shoulders, but at our house they’re a fun curiosity. One summer a couple years ago, we spotted a black snake eating baby birds from a nest just under the eaves. It was too late to rescue the birds, so we let nature take its course. But then the snake, who had climbed the gutter to snag the babies, couldn’t figure out how to get down. We watched it traverse the gutter two stories above the back yard, trying to find a way down before the threatening storm clouds broke, getting as frantic as a slow-moving reptile with no emotional facial features can be.

Andrew felt worried for it and so cobbled together a contraption made of a window-washing pole and branches from the yard held on with zip ties. It formed a sort of snake ladder that allowed the perpetrator to escape. You can see the slow-speed getaway below:

Black snakes are constrictors, as is obvious by this one’s ability to cling to the pole and branches to descend 30 feet or more from our roof. This means they don’t need venomous fangs to kill their prey – they simply squeeze them to death.

Are all nonvenomous snakes constrictors? At a recent excursion to our local nature center, I learned about one snake that isn’t a constrictor but also doesn’t have the traditional venomous fangs. Instead, hognose snakes have fangs toward the back of their mouths, and they use them in a very unusual way…

Why do hognose snakes have a “popping” tooth?

Hognose snakes are a popular pet snake. People oftentimes catch them and tame them because they’re easy to train and nonaggressive. They’re named for their unique snub-nosed head that gives them a bit of a “Miss Piggie” vibe:

Their “nose” is really an upturned scale - Photo by Tim Jasinski

You’ll notice that the hognose’s fangs aren’t in the normal spot – they’re farther back in their mouth instead of up front and prominent. The latin name for these snakes is Heterodon, which means “different tooth” because of this particular feature.

Hognose snakes are short and squat, usually only around 2 feet long. Their main diet is toads, which they dig up using their tiny upturned noses. However, toads have realized that if they puff themselves up with air, they can appear to be too big to eat. Frogs and toads will puff up upon encountering any dangerous predator, not just snakes – crows, coyotes, even people have experienced this cool defense mechanism.

Hognose snakes have come up with a solution, however; they use their rear fangs to pop the inflated frog so they can swallow it. Technically, the rear fang doesn’t deliver venom but their saliva may have physiological effects that help immobilize toads and make swallowing easier.

Talk about extra-specific animal adaptations!

Another cool fact about hognose snakes? When they feel threatened, their first line of defense is to spread out their necks like a cobra:

If that doesn’t work and you don’t run away, they will then play dead by flipping onto their backs, belly up. They even flop out their tongues for added effect:

Nothing to see here, move along… Photo by J.D. Willson

Puffing itself up and playing dead are both forms of protean behavior, or the act of behaving unnaturally in order to confuse a predator. Zigging and zagging while escaping is another protean behavior, as are other unique defenses like changing color or squirting ink like an octopus. Just a few moments of confusion are all the prey animal needs to escape.

Have you encountered a hognose snake or did you have one as a pet? They are apparently docile and easygoing, but I’ve never encountered one.

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Weird Nature:

(click to view)

A cool example of inosculation – tree fusion