Rear-Fanged Snakes


I talk to a lot of kids about reptiles, and inevitably they will ask me, "Is that poisonous?"


I love that question, because it allows me to make a joke that will, in the end, be informative. I say, "No! You could eat it."


The resulting expression, half confused and half disgusted, is priceless. I go on to explain that "poisonous" means something that you shouldn’t eat or rub in your eyes. "Venomous" means something that can inject you with poison, either by stinging or biting. In most cases, the animal I am displaying is neither.


I then like to take things a step further and explain that just because something is venomous, it doesn’t mean it’s dangerous. That is a new concept to most kids, who have typically been taught that venomous animals are lethal. However, that’s ridiculous. Ants are venomous. Bees are venomous. While they are painful and annoying, they’re by no means lethal.


Most venomous snakes are also harmless. In fact, they are more harmless than ants because of their reluctance to bite. Here in California, we have 33 species of snake. Of the dozen or more snakes that are venomous, only the six species of rattlesnake are considered dangerous.


The majority of venomous snakes fall into a class we call "rear-fanged." That refers to snakes whose fangs are located in the back of their jaw instead of up front. The overwhelming majority of rear-fanged snakes are harmless. These snakes tend to have milder toxins, which are designed to subdue small prey, such as lizards and frogs. There are two rear-fanged snakes that are actually quite common in the pet trade: Asian vine snakes (primarily Ahaetulla prasina) and Western hognose snakes (Heterodon basics).


So, let’s say a customer asks to handle the vine snake you are offering for sale. I always mention beforehand that they are technically venomous. The last thing you want a customer to think is that you have tricked them into handling a dangerous animal.


Then I inform them that there is no need to worry. To get one to bite, you first would have to either make the snake believe you are a lizard, as that is its natural prey, or scare it so badly that it would bite as a last resort—they’d rather flee. In 40 years, I have never seen a human manage to imitate a lizard that well.


For the sake of argument, let’s say that you did manage to convince the snake to bite you. Rear-fanged snakes need to work their jaws forward to get the fangs into position to envenomate, and this takes some time. Once the fangs are in position, the snake would need to chew for a few minutes to work a substantial amount of venom into the wound.


I find it hard to imagine anyone willing to put up with this behavior long enough to become envenomated, but let’s say you did. The toxicity of the bite might be something on the order of a bee sting. Now, in all fairness, some people die from bee stings, as there is always the remote possibility of an allergic reaction. However, at this point you are looking at odds so remote one might more reasonably fear a lightning strike—which is more likely—while holding that snake.


It turns out that both the vines and the hognoses are some of the most charming snakes in the hobby. Now that we’ve conquered the nonsensical terror they invoke, let’s talk about care.


Vine snakes are tropical and arboreal, so a warm, moist and tall cage is in order. They have the same sort of lifestyle as our native green snakes. They spend their days foraging for lizards high in the brush and descend at night to the floor to sleep. Give them an 80-90 degree temperature span, strong UV light and spray down the cage with water every morning and evening.


They readily feed on house geckoes and anoles. This can be problematic for potential customers. It is hard to guarantee a year-round supply of live food and I have never seen one willing to take pre-killed. Even if you feel confident in providing food, their predilection is expensive relative to mouse eaters. The only good solution is to feed them as frequently as possible when food is readily available and hope they will have enough stores to tide them through the winter.


The vine snake is a thing of real beauty—a long, impossibly slender and elegant body with a forest green topside and yellow to cream belly. Their heads are designed to look like a leaf, so their noses are long and pointed. They can extend their bodies forward without a brace for gravity defying lengths. Like chameleons, they have binocular vision, a necessity for arboreal hunting. Because their eyes can focus forward and they have unusual horizontal pupils, they can stare directly at you with what looks like an air of bemused perplexity.


Equally charming is the hognose. Their stout bodies are patterned with caramel to brown coloring against a cream background. Their eyes have a permanently stern expression—much like that of a rattler—but this is offset with an adorable upturned nose. The truth is that the nose is designed to help them root though leaf litter in search of prey, but the visual effect is pure cute.


Note that there are three species of hogs native to the U.S. and a few unrelated others from around the world. There are Southerns, Westerns—including a Mexican subspecies—and Easterns. All three are primarily toad-eaters in the wild, but only the Westerns—distinguished by their black ventral scales—will readily switch over to mice. As small toads are even harder and more expensive to provide year-round, I recommend sticking to the Westerns.


Care for hognoses is pretty basic; treat them like any colubrid—think corn or king snakes. Keep the temperature around 75-85 degrees, and make sure there’s a hiding space, water bowl and shavings. I prefer Aspen bedding with hognoses, as it tends to hold form so that, as they move through it, it retains tunnels for their repeated use. Feed them with mice once or twice a week.


Should you happen across a toad, it might be a temptation to try it out on your hog. DO NOT DO THIS! When confronted with a new food, snakes sometimes decide that this is their new preference and getting them to eat mice again can be a struggle. The headache is not worth the free meal!


I know that many of my peers in this industry operate in states with little to no supervision of venomous snakes—including front-fanged species—and for them this article might seem laughable. I am pleased to be in a state with strict controls against private ownership of truly dangerous snakes. I think that the inevitable accidents and escapes with cobras, vipers, etc. will shine a rather poor light on our hobby and business, and I am happy to not be a part of that.


These snakes, on the other hand, are worthy ambassadors sent to disarm those predisposed to fear and hostility. Let them work their magic! PB


Owen Maercks has enjoyed being immersed in the world of professional herpetoculture for nearly 40 years. His store, the East Bay Vivarium in Berkeley, Calif., is one of the oldest and largest herptile specialty stores in the U.S.