Snakes
Snake Facts
Snakes are among the most fascinating - and widely feared - creatures on earth. While there are approximately 3,400 snake species, less than 400 species are venomous. Below are just a few of the many amazing facts about these slithering, tongue-flicking reptiles.
General Snake Facts
- Taxonomic Suborder: Serpentes
- Number of Extant Species: Over 3,000
- Size Range: 4 in. - 25 ft. long; .2 cm - 1 ft. in diameter; .02 oz. - 550 lbs.
- Average Lifespan in the Wild: 1-15 years, depending on the species
- Identifying Characteristics: long, narrow, legless body covered in overlapping scales; round eyes on either side of the head; lack of ears and eyelids; forked tongue.
Snake Geography & Habitat
Snakes can be found throughout most of the world, except for Antarctica, Iceland, Greenland, Ireland, and New Zealand. Sea snakes inhabit the Pacific and Indian oceans.
The preferred habitat of a snake depends on the species. Some snakes live in the rainforest, some in the desert and others in water. Since snakes are ectotherms and unable to internally regulate their body temperatures, they cannot live in overly cold habitats.
Snake Diet
All snakes are carnivores, but their specific diets typically vary with their species and habitats. They are opportunistic feeders that eat when food is available, which also may vary with the habitat. Some snakes eat a few times a week, while others only eat a few times per year. Because snakes are rarely active, they don't require much food to survive.
Common snake foods include:
Snake Behavior
- Activity: Different snake species vary in activity level; however, snakes are most active when temperatures are mild. Because they are ectotherms, they are unable to internally regulate their body temperatures and cannot survive in extreme cold or heat.
- Reproduction: Mating season is typically in the spring, when snakes emerge from brumation. While all snakes engage in internal fertilization, some lay eggs and some give birth to live snakes.
- Molting: Snakeskin does not grow, but snakes do. When a snake begins to outgrow its skin, it will molt (shed) the outgrown layer.
- Tongue-Flicking: In addition to using their eyes and noses, snakes also use their tongues to pick up important environmental stimuli. A snake voluntarily flicks its tongue to pick up chemical particles from the air, and its tongue delivers the particles to the Jacobsen's organ - located at the roof of the snake's mouth. This organ interprets the signals and mediates many important behaviors such as hunting and finding a mate.
- Predation/Feeding: As predators, snakes hunt a variety of live animals. Venomous snakes kill their prey by injecting poisonous venom through their teeth when they bite, immobilizing their victims. Non-venomous snakes kill by either constricting animals with their bodies or eating animals alive.
- Biting: Both venomous and non-venomous species of snakes have fangs that they use to attack prey and defend themselves from threats. When venomous snakes bite, they may voluntarily inject their poisonous venom.
Identify Signs of Snakes
In general, most snakes aren't very active, so signs of snakes may be hard to find. The best ways to identify the presence of snakes in your home or yard include:
- visual identification
- molted snakeskin
- snake tracks in dirt, dust or sand: continuous S-shaped pattern
- signs of bites on dogs or livestock
- rattling sound: indicates the presence of rattlesnakes
Identifying Venomous Snakes
The snake classification that concerns most humans is that of poisonous vs. non-poisonous. In the United States, there are five types of venomous (poisonous) snakes: rattlesnakes, copperheads, water moccasins (a.k.a. cottonmouths), sea snakes and coral snakes. Rattlesnakes, copperheads and cottonmouths are all classified as pit vipers. Venomous snakes in the U.S. may be distinguishable from non-venomous snakes in the following ways:
- triangular heads
- egg-shaped, vertical pupils
- heat-sensing "pits" on either side of the head, between the eye and nostril
- scales on underside of tail, span across in single rows
- less prominent, spoon-shaped heads
- perfectly round pupils
- lack of "pits" between eye and nostril
- scales on underside of tail, span across in split rows of two
- swim with head out of water
- live in the ocean
- swim with most of their bodies above water
- less prominent, almost spoon-shaped heads
- definitive color pattern: red, yellow, black, yellow, red...
Fun Facts
- Molting (shedding scales) helps snakes get rid of ticks and parasites.
- Snakes possess rear-facing teeth, which help keep prey from escaping their mouths.
- Like pigs, male moles are called "boars" and female moles are called "sows".
- Snakes swallow their food whole.
- The longest snake species is the reticulated python, which can grow up to 25 feet, and the heaviest snake is the green anaconda, which can weigh up to 550 lbs. The smallest species is the Barbados thread snake, which only grows to be about 4 inches long and .02 oz.
- A reported 7,000-8,000 venomous snakebites occur annually in the United States, and from these there are an average of 5 deaths per year. The impressive survival rate of venomous snakebites in the United States versus other countries is credited to our advances in medicine and antivenin treatments.
