9 Things You Didn't Know About Snakes

Snakes have played a role in our ecosystem for millions of years, thought to have evolved from terrestrial lizards sometime around the Middle Jurassic epoch. Since then, they've slithered into timeless myths — remember the resident trickster in the Garden of Eden? — inciting fear with their reptilian tongues and sometimes lethal venom. But apart from being the source of one of the most common phobias known to man, snakes are wildly fascinating. From their vast size variation to their hypnotizing ability to swallow things several times their size, discover the most interesting (albeit slightly freaky) facts about these notoriously polarizing creatures.

1. Snakes Live (Almost) Everywhere

There are more than 3,000 species of snakes on the planet, some living as far north as the Arctic Circle in Scandinavia, others as far south as Australia. They're found on every continent except Antarctica (although the countries of Ireland, Greenland, Iceland, and New Zealand have also managed to remain snake-free). Some species prefer to live high up — in the Himalayas, for example — while others thrive below sea level.

2. They Have Peculiar Infrastructures

Without a traditional torso to accommodate major organ systems, snakes must house their paired organs, like kidneys and ovaries, from front to back instead of side-by-side. They have only one functional lung, besides. Their hearts are adjustable, able to move around in the absence of a diaphragm, which protects them from being squished when large meals are swallowed whole and squeezed tightly through the esophagus.

3. They Smell With Their Tongues

Few things say snake like a hiss and simultaneous flick of a forked tongue. Their signature move allows them to collect airborne particles and pass them to olfactory organs in the mouth. Put simply, this is how they smell. The split tongue gives them a somewhat directional sense of smell and taste. By keeping their tongues constantly flicking about, they're able to sample chemicals in the air, ground, and water and use them to determine the presence of prey or predators nearby.

4. They Hear Through Vibrations

Snakes have acute vibration sensitivity. Their bellies can detect even the faintest movement in the air and on the ground, a warning that a predator or prey may be approaching. This makes up for their lack of eardrums. Although they have fully developed inner-ear structures, snakes don't have visible ears. Instead, some — such as pit vipers, pythons, and some boas — have infrared-sensitive receptors in grooves along their snouts, which enable them to sense the radiated heat of warm-blooded animals nearby.

5. They Eat Whatever Fits in Their Mouths

Snakes are exclusively carnivorous and will eat anything from small lizards, other snakes, small mammals, birds, eggs, fish, snails, and insects to large mammals like jaguars and deer. Because they eat their prey in one big gulp, the size of the snake determines the size of its food. A younger python may start with lizards or mice, moving up to small deer and antelopes as it increases in age and size. According to the San Diego Zoo, they regularly consume animals up to 20 percent their own body size.

6. They Range From 4 Inches to 30 Feet in Length

Most snakes are relatively small creatures, about 3 feet in length. Although the extinct Titanoboa could grow up to 50 feet long roughly 60 million years ago, the longest modern-day snake — the reticulated python, native to South and Southeast Asia — measures in at 30 feet. At the other end of the ruler, the smallest is the Barbados threadsnake — Leptotyphlops carlae — only 4 inches long.

7. The Heaviest Snakes Can Weigh 500-Plus Pounds

South America’s green anaconda can grow to more than 29 feet in length and reach a weight of more than 550 pounds. Cumbersome on land, they live near languid rivers and swamps and spend much of their time in the water, where they can slink about much more quickly. With eyes and nostrils on top of their heads like alligators, they stalk their prey while keeping their body hidden beneath the surface. To maintain their impressive mass, green anacondas feast on wild pigs, deer, birds, turtles, capybara, caimans, and even the occasional jaguar, which they will first strangle by constriction. Their jaws are connected by elastic ligaments, which allow them to swallow their dinner whole, sometimes lasting them for weeks or even months before they require another meal.

8. Some Can Fly

As if the slithering weren't disturbing enough for some, there are five species of venomous, tree-dwelling snakes that can, indeed, fly. Found in Sri Lanka and Southeast Asia, they technically glide rather than fly, first using the lower half of their bodies to propel themselves from a J-shaped hang, then contorting their frames into an "S" and flattening to twice their normal widths to trap air. By undulating back and forth, they can actually make turns. Experts note that these soaring snakes glide with even more agility than their mammalian counterparts, flying squirrels.

9. Nearly 100 Snake Species Are Endangered

According to the International Union for Conservation of Nature and Natural Resources (IUCN), 12 percent of snake species are threatened and 4 percent are near-threatened. There are 97 species and one subspecies that are endangered, and populations are declining across the board due to habitat destruction, overexploitation, disease, invasive species, and climate change. Sea snakes, constrictors, and several species of garter snake are among the endangered.