With approximately 3,700 known snake species across the world, snakes occupy various habitats in every temperate region of our planet.
Of these species, around 600 are venomous, and a fraction—about 200—can be dangerous to humans. Snake species are scientifically classified under the class Reptilia, in the order Squamata, and the suborder Serpentes, derived from the Latin "serpō," which means "to crawl or creep."
Snakes are exclusively carnivorous, preying on mammals, fish, amphibians, invertebrates, as well as other reptiles, including other snakes. Trivia note: there are no snakes in Greenland, Iceland, Ireland or New Zealand.
The anatomy of a snake is highly adapted for their predatory lifestyle, featuring specializations such as venomous teeth, a flexible skull, infrared-sensing pits to locate warm-blooded prey, and digestive enzymes capable of breaking down bones, feathers, and hair. Snakes lack external ear openings but can sense vibrations through their bodies. Their acute sense of smell is enhanced by the Jacobson's organ, which interprets information from their forked tongue.
From an ecological perspective, snakes are invaluable.
They manage rodent populations and are key prey items for numerous species. Venom, while a defense mechanism and a means to immobilize prey, has contributed significantly to medical science. Substances like Captopril®, an ACE inhibitor for heart conditions, and Integrilin®, an anti-clotting agent, are among the medical breakthroughs derived from snake venom, demonstrating its research and therapeutic potential.
Understanding the behaviors and habitats of snakes is crucial for the effective design and implementation of snake fencing solutions. By educating customers on the ecological and medical importance of snakes, we can promote a balanced view that appreciates their role in nature and underscores the benefits of having appropriate fencing to ensure human safety and the conservation of wildlife.
Rattlesnakes belong to the subfamily Crotalinae, also known as pit vipers, which are identifiable by the two infrared (heat-sensing) pits situated between their eyes and nostrils. This subfamily includes species such as rattlesnakes, massasaugas, water moccasins (cottonmouths), and copperheads. In total, there are approximately 155 Crotaline species in the Americas, of which 30 are recognized as rattlesnake species. Seven species reside in California, while Arizona has the highest diversity with 13 species.
Rattlesnakes are characterized by their robust bodies, sizeable triangular heads, keeled scales, and front-hinged fangs. Their tails feature a rattle made up of interlocking segments, serving as a warning device to potential predators and to deter too-close encounters. Their vertical-slit pupils enable them to see better in low-light conditions, enhancing shape resolution and depth perception for efficient prey detection.
The coloration and patterns of rattlesnakes are highly adapted to their environments, with a significant degree of variation even within the same species. These patterns include an array of markings such as triangular shapes, blotches, and lined borders, which aid in camouflage. The belly scales, contrary to playful descriptions, are not velvety but exhibit a metallic sheen. Tails are typically marked with bands and end in the characteristic rattle.
In California, the variety of rattlesnake species and their subspecies contribute to the state's rich biodiversity. Although the yellow-bellied sea snake occasionally appears along the southern Pacific coastline, rattlesnakes are the principal venomous snakes posing a risk to humans in California. Adult rattlesnakes typically measure between 33 to 65 inches in length, with the western diamond-backed rattlesnake occasionally growing up to 90 inches. Rattlesnake offspring, known as neonates, are viviparous, contrasting with the oviparous reproduction of many other snake species. Neonates are around 10 inches long at birth and are small enough to pass through openings slightly larger than ¼ inch. Therefore, selecting and installing appropriate exclusion fencing is crucial to prevent entry by these snakes. Hey! We know experts who do that!!!
So…what’s the deal with venom?
I’m so glad you asked. Rattlesnake venom is a sophisticated blend of proteins that has evolved to immobilize prey by targeting their organs and cells. Lacking limbs, snakes have adapted through natural selection to either constrict their prey or use venom to incapacitate them. Constriction involves the snake seizing the prey with its mouth and wrapping its body around the captured animal, applying pressure to prevent breathing and eventually leading to subjugation and consumption.
Envenomation, which rattlesnakes use, involves delivering venom through specialized, needle-like fangs. Rattlesnakes have a distinctive triangular head, accommodating a venom gland located posterior to each eye. Members of the Viperidae family, such as rattlesnakes, possess front-hinged fangs, enabling them to extend their fangs to inject venom effectively. In contrast, the Elapidae family—which includes cobras and coral snakes—have fixed fangs at the front of their mouth. Other snake families may have fangs located further back in the mouth and possess different mechanisms for venom delivery, such as the Duvernoy’s gland, which secretes venom along the teeth. Still, there are other species such as gartersnakes that have mildly toxic saliva which is harmless to humans but may cause mild skin irritation in some cases.
The injection of venom by front-fanged snakes is a voluntary action, allowing snakes to decide when to envenomate and how much venom to expel. Contrary to common belief, rattlesnakes often opt for camouflage and silence as their primary defense mechanism. Rattling is a secondary defensive strategy, intended as a warning. Rattlesnakes may strike without rattling and do not always release venom when they do so, which can occur if they feel threatened or provoked. Due to these behaviors, it is critical to remain vigilant in environments where rattlesnakes may be present.
How many people are bitten by rattlesnakes?
Annually, an estimated 7,000 to 8,000 people in the U.S. suffer bites from venomous snakes. Among these incidents, fatalities are extremely rare, with the fatality rate being approximately one in 50 million, leading to an average of 5 to 6 deaths per year. To contextualize, the number of fatalities from snake bites is lower than those resulting from incidents such as dog bites, bee stings, lightning strikes, or even forklift-related accidents, which account for roughly 85 fatalities annually. While the notion of a snake bite can be alarming, the probability of occurrence is relatively low. The best prevention is to maintain a safe distance and stay vigilant in environments where snakes are present. It is advised to never attempt to handle or disturb a rattlesnake, as this significantly increases the risk of being bitten. Rattlesnakes are capable of striking within a fraction of a second, much quicker than any defensive reaction a person could attempt. On the contrary, data on how many snakes are bitten by humans each year is less clear, but we’ll look into it.
What is a dry bite?
A 'dry bite' is a term used when a rattlesnake or coral snake bites but does not inject venom into the wound. It is an occurrence that is not as rare as one might think; estimates suggest that between 20-40% of rattlesnake bites and about 50% of coral snake bites fall into this category. Producing venom is energetically costly for snakes. As a result, they tend to conserve their venom, which is essential for hunting and self-defense and are selective about its use. On average, snakes may only feed once every two weeks, with juvenile rattlesnakes feeding approximately once a week, and certain species may feed as infrequently as five to six times per year. Given these low feeding frequencies, it is crucial for snakes to manage their venom reserves efficiently, prioritizing its use for securing food rather than expending it on defensive actions.
Seeing red…well, infrared.
The infrared receptors, or pit organs, in snakes, function similarly to our eardrums and have a 'stereo' effect in detecting prey, other organisms, and the surrounding environment. Rattlesnakes utilize these receptors to ascertain the direction, size, and distance of prey within their vicinity. They are so sensitive that these snakes can detect temperature variations as slight as 0.2°C against the ambient temperature.
How often do snakes visit residential areas?
It's difficult to quantify the frequency of snake visits to residential areas; however, it is known that homes located within or adjacent to natural habitats often report snake sightings. Research conducted by the USGS Southwestern Biological Science Center near Montezuma Castle National Monument, just north of Phoenix, Arizona, has recorded several instances of western diamond-backed rattlesnakes, tagged for a study, appearing near residences without the homeowners' knowledge. In one documented case, a rattlesnake was found only one meter away from a front door[1]. Therefore, it can be inferred that snakes may visit residential areas more frequently than incidents are reported. Rattlesnakes are habitual creatures, predominantly engaged in activities such as foraging, thermoregulating, and seeking mates. There are, nevertheless, preventative measures that homeowners can take to reduce encounters with these reptiles. These measures include the installation of physical barriers like snake-proof fencing and the modification of landscaping to make the area less attractive to snakes.Are rattlesnakes good climbers?
Rattlesnakes are not adept climbers. It is rare for them to ascend trees or shrubs, and a well-constructed fence can greatly reduce the likelihood of them entering your yard. In contrast, other snake species such as whipsnakes, gophersnakes, and kingsnakes, which are non-venomous, exhibit more proficient climbing skills and can scale various structures, including the stucco siding on houses. While no barrier system is entirely infallible, a fence that is properly designed and installed remains the most effective method for deterring rattlesnakes. At SnakeFencing.com, our team of highly knowledgeable wildlife biologists and certified fencing contractors specialize in custom fencing solutions. We are prepared to assist you in exploring your options and crafting a plan that suits your specific requirements, allowing you to safely enjoy your outdoor environment.[1] Nowak, E.M., T. Hare, and J. McNally. 2002. Management of “Nuisance? Vipers: Effects of Translocation of Western Diamond-Backed Rattlesnakes (Crotalus atrox). Biology of the Vipers (G. W. Schuett et al., Editors, 2002, Eagle Mountain Publ., Eagle Mountain, Utah.