
Crab Facts: Claws, Shells & Secret Behaviors
Crabs are crustaceans found on every continent with over 7,000 species. Discover why crabs walk sideways, trade shells, and grow claws stronger than jaws.

Snakes are limbless reptiles with 3,000+ species worldwide. Learn about snake senses, venom, habitats, and their important roles in controlling rodent populations.
Snakes are limbless reptiles found on every continent except Antarctica. With over 3,000 species ranging from 4 inch threadsnakes to 30 foot pythons, these predators display remarkable diversity.
Snakes have incredibly flexible bodies with 200 to 400 vertebrae, far more than mammals. Their ribs attach to nearly every vertebra, providing structure while maintaining flexibility. Snake jaws are not fused like mammal jaws.
Snakes rely on multiple senses to locate prey. Their forked tongues collect scent particles from the air and transfer them to the Jacobson organ in the roof of their mouths for analysis. Pit vipers, pythons, and boas possess specialized heat sensing organs that detect temperature differences as small as 0.003 degrees Celsius.
Snakes employ four primary movement methods. Serpentine motion involves side to side body waves pushing against surface irregularities. Rectilinear motion uses belly scales to grip surfaces while muscles pull the body forward in a straight line.
Venomous snakes use modified salivary glands to produce venom delivered through hollow or grooved fangs. Venom types include neurotoxins that paralyze prey, hemotoxins that destroy blood cells, and cytotoxins that break down tissue. Different species have evolved venom suited to their primary prey.
Most snakes lay eggs, though about 30% give birth to live young. Egg laying species find warm, protected locations and may produce 5 to 100 eggs depending on species size. Snakes shed their skin 2 to 4 times yearly as they grow.
Snakes appear in mythology worldwide, from the biblical serpent to the Aztec feathered serpent Quetzalcoatl.
Ancient Egyptians worshipped the cobra goddess Wadjet and used snake imagery on pharaoh crowns.
Snake venom has been used medicinally for thousands of years, now yielding modern pharmaceuticals.
Rod of Asclepius featuring a snake became the symbol of medicine used by doctors worldwide.
Fear of snakes, ophidiophobia, is one of the most common phobias, possibly evolved for survival.
Research revealed pit vipers detect temperature differences of 0.003 degrees Celsius.
Studies showed only about 600 of 3,000 snake species have medically significant venom.
Scientists discovered flying snakes flatten their bodies to glide between trees.
Research proved snake hearts can move along their bodies during large meal digestion.
Studies documented that snake venom compounds are being developed into life saving medicines.
Snakes inspire both fear and reverence across virtually all human cultures.
Snake handling remains part of religious practices in some Appalachian churches.
Reptile keeping as a hobby has made snakes popular pets worldwide.
Conservation efforts work to protect snakes despite widespread fear and persecution.
Antivenom development saves thousands of lives annually from snakebite.
Before widespread human settlement, snakes occupied virtually every ecosystem on Earth except Antarctica. They naturally controlled rodent populations and played essential roles in food webs. Most snakes lived their lives without human encounters in balanced ecosystems.
After human expansion, many snake populations face persecution from fear based killing, habitat loss, and road mortality. Millions of snakes are killed unnecessarily each year by people who cannot distinguish venomous from harmless species. Conservation efforts now educate communities about snake benefits and identification to reduce unnecessary killings.
Snakes can go months without eating after consuming a large meal
The inland taipan has the most toxic venom, enough to kill 100 adult humans
Flying snakes glide between trees by flattening their bodies into wing shapes
Some sea snakes can breathe through their skin, absorbing oxygen from water
A snake's heart can move along its body to protect it during large meals
Tentacled snakes have twin appendages on their snouts that sense fish movement
Snakes control rodent populations that would otherwise damage crops and spread disease
Snake venom research is yielding new medicines for heart disease, pain, and cancer
Snakebite kills up to 138,000 people annually, mostly in developing countries
Habitat loss and persecution threaten many snake species worldwide
Understanding snakes helps reduce unnecessary killings of harmless species
How much do you know? Take this quick quiz to find out!
Only 600 species are venomous. Most of 3,000 snake species are completely harmless to humans.
Hearts move during digestion. The heart slides along the body to avoid being crushed by large prey.
Some snakes fly. Flying snakes flatten their bodies and glide up to 100 feet between trees.
Inland taipan is most venomous. One bite has enough venom to kill 100 adult humans.
They smell with tongues. Forked tongues collect scent particles for the Jacobson organ to analyze.
Snakes have hundreds of vertebrae. 200 to 400 vertebrae give them remarkable flexibility.
No, only about 600 of the 3,000+ snake species are venomous. Of those, only around 200 have venom potent enough to seriously harm humans. Most snakes are harmless constrictors or small species that eat insects and small prey. Venomous species include vipers, cobras, mambas, and sea snakes.
This article is reviewed by the Pagefacts team.
Editorial Approach:
This article reveals only 600 of 3,000 snake species are venomous, explains how their hearts move during digestion to avoid being crushed, and shows how pit vipers see heat signatures accurate to 0.003 degrees.
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